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1.
Dunsmore BC Jacobsen A Hall-Stoodley L Bass CJ Lappin-Scott HM Stoodley P 《Journal of industrial microbiology & biotechnology》2002,29(6):347-353
Biofilms of sulphate-reducing Desulfovibrio sp. EX265 were grown in square section glass capillary flow cells under a range of fluid flow velocities from 0.01 to 0.4
m/s (wall shear stress, τw, from 0.027 to 1.0 N/m2). In situ image analysis and confocal scanning laser microscopy revealed biofilm characteristics similar to those reported for aerobic
biofilms. Biofilms in both flow cells were patchy and consisted of cell clusters separated by voids. Length-to-width ratio
measurements (l
c:w
c) of biofilm clusters demonstrated the formation of more “streamlined” biofilm clusters (l
c:w
c=3.03) at high-flow velocity (Reynolds number, Re, 1200), whereas at low-flow velocity (Re 120), the l
c:w
c of the clusters was approximately 1 (l
c:w
c of 1 indicates no elongation in the flow direction). Cell clusters grown under high flow were more rigid and had a higher
yield point (the point at which the biofilm began to flow like a fluid) than those established at low flow and some biofilm
cell aggregates were able to relocate within a cluster, by travelling in the direction of flow, before attaching more firmly
downstream.
Received 01 February 2002/ Accepted in revised form 16 July 2002 相似文献
2.
Planktonic nitrate-reducing bacteria and sulfate-reducing bacteria in some western Canadian oil field waters 总被引:3,自引:0,他引:3
Oil fields that use water flooding to enhance oil recovery may become sour because of the production of H2S from the reduction of sulfate by sulfate-reducing bacteria (SRB). The addition of nitrate to produced waters can stimulate
the activities of nitrate-reducing bacteria (NRB) and control sulfide production. Many previous studies have focused on chemolithotrophic
bacteria that can use thiosulfate or sulfide as energy sources while reducing nitrate. Little attention has been given to
heterotrophic NRB in oil field waters. Three different media were used in this study to enumerate various types of planktonic
NRB present in waters from five oil fields in western Canada. The numbers of planktonic SRB and bacteria capable of growth
under aerobic conditions were also determined. In general, microbial numbers in the produced waters were very low (<10 ml−1) in samples taken near or at wellheads. However, the numbers increased in the aboveground facilities. No thiosulfate-oxidizing
NRB were detected in the oil field waters, but other types of NRB were detected in 16 of 18 produced water samples. The numbers
of heterotrophic NRB were equal to or greater than the number of sulfide-oxidizing, chemolithotrophic NRB in 12 of 15 samples.
These results showed that each of the oil fields contained NRB, which might be stimulated by nitrate amendment to control
H2S production by SRB. Journal of Industrial Microbiology & Biotechnology (2002) 29, 83–92 doi:10.1038/sj.jim.7000274
Received 20 February 2002/ Accepted in revised form 14 May 2002 相似文献
3.
The effect of long-term nitrate treatment on SRB activity,corrosion rate and bacterial community composition in offshore water injection systems 总被引:1,自引:0,他引:1
Bødtker G Thorstenson T Lillebø BL Thorbjørnsen BE Ulvøen RH Sunde E Torsvik T 《Journal of industrial microbiology & biotechnology》2008,35(12):1625-1636
Biogenic production of hydrogen sulphide (H2S) is a problem for the oil industry as it leads to corrosion and reservoir souring. Continuous injection of a low nitrate
concentration (0.25–0.33 mM) replaced glutaraldehyde as corrosion and souring control at the Veslefrikk and Gullfaks oil field
(North Sea) in 1999. The response to nitrate treatment was a rapid reduction in number and activity of sulphate-reducing bacteria
(SRB) in the water injection system biofilm at both fields. The present long-term study shows that SRB activity has remained
low at ≤0.3 and ≤0.9 μg H2S/cm2/day at Veslefrikk and Gullfaks respectively, during the 7–8 years with continuous nitrate injection. At Veslefrikk, 16S rRNA
gene based community analysis by PCR–DGGE showed that bacteria affiliated to nitrate-reducing sulphide-oxidizing Sulfurimonas (NR–SOB) formed major populations at the injection well head throughout the treatment period. Downstream of deaerator the
presence of Sulfurimonas like bacteria was less pronounced, and were no longer observed 40 months into the treatment period. The biofilm community
during nitrate treatment was highly diverse and relative stable for long periods of time. At the Gullfaks field, a reduction
in corrosion of up to 40% was observed after switch to nitrate treatment. The present study show that nitrate injection may
provide a stable long-term inhibition of SRB in sea water injection systems, and that corrosion may be significantly reduced
when compared to traditional biocide treatment. 相似文献
4.
In a batch culture experiment the microaerophilic Campylobacter-like bacterium “Spirillum” 5175 derived its energy for growth from the reduction of nitrate to nitrite and nitrite to ammonia.
Hereby, formate served as electron donor, acetate as carbon source, and l-cysteine as sulfur source. Nitrite was quantitatively accumulated in the medium during the reduction of nitrate; reduction
of nitrite began only after nitrate was exhausted from the medium. The molar growth yield per mol formate consumed, Ym, was 2.4g/mol for the reduction of nitrate to nitrite and 2.0 g/mol for the conversion of nitrite to ammonia. The gain of
ATP per mol of oxidized formate was 20% higher for the reduction of nitrate to nitrite, compared to the reduction of nitrite
to ammonia. With succinate as carbon source and nitrite as electron acceptor, Ym was 3.2g/mol formate, i.e. 60% higher than with acetate as carbon source. No significant amount of nitrous oxide or dinitrogen
was produced during growth with nitrate or nitrite both in the presence or absence of acetylene. No growth on nitrous oxide
was found. The hexaheme c nitrite reductase of “Spirillum” 5175 was an inducible enzyme. It was present in cells cultivated with nitrate or nitrite
as electron acceptor. It was absent in cells grown with fumarate, but appeared in high concentration in “Spirillum” 5175 grown
on elemental sulfur. Furthermore, the dissimilatory enzymes nitrate reductase and hexaheme c nitrite reductase were localized in the periplasmic part of the cytoplasmic membrane. 相似文献
5.
Anaerobic oxidation of alkanes by newly isolated denitrifying bacteria 总被引:11,自引:0,他引:11
The capacity of denitrifying bacteria for anaerobic utilization of saturated hydrocarbons (alkanes) was investigated with
n-alkanes of various chain lengths and with crude oil in enrichment cultures containing nitrate as electron acceptor. Three
distinct types of denitrifying bacteria were isolated in pure culture. A strain (HxN1) with oval-shaped, nonmotile cells originated
from a denitrifying enrichment culture with crude oil and was isolated with n-hexane (C6H14). Another strain (OcN1) with slender, rod-shaped, motile cells was isolated from an enrichment culture with n-octane (C8H18). A third strain (HdN1) with oval, somewhat pleomorphic, partly motile cells originated from an enrichment culture with aliphatic
mineral oil and was isolated with n-hexadecane (C16H34). Cells of hexane-utilizing strain HxN1 grew homogeneously in the growth medium and did not adhere to the alkane phase, in
contrast to the two other strains. Quantification of substrate consumption and cell growth revealed the capacity for complete
oxidation of alkanes under strictly anoxic conditions, with nitrate being reduced to dinitrogen.
Received: 3 August / Accepted: 6 October 1999 相似文献
6.
The intracellular ratio of 2-oxoglutarate to glutamine has been analyzed under nutritional conditions leading to different activity levels of nitrate-assimilating enzymes in Phormidium laminosum (Agardh) Gom. This non-N2-fixing cyanobacterium adapted to the available nitrogen source by modifying its nitrate reductase (NR; EC 1.7.7.2), nitrite reductase (NiR; EC 1.7.7.1) and glutamine synthetase (GS; EC 6.3.1.2) activities. The 2-oxoglutarate/glutamine ratio was similar in cells adapted to grow with nitrate or ammonium. However, metabolic conditions that increased this ratio [i.e., nitrogen starvation or l-methionine-d,l-sulfoximine (MSX) treatment] corresponded to high activity levels of NR, NiR, GS (except in MSX-treated cells) and glutamate synthase (GOGAT; EC 1.4.7.1). By contrast, metabolic conditions that diminished this ratio (i.e., addition of ammonium to nitrate-growing cells or addition of nitrate or ammonium to nitrogen-starved cells) resulted in low activity levels. The variation in the 2-oxoglutarate/glutamine ratio preceded the changes in enzyme activities. These results suggest that changes in the 2-oxoglutarate/glutamine ratio could be the signal that triggers the adaptation of P. laminosum cells to variations in the available nitrogen source, as occurs in enterobacteria.Abbreviations Chl
chlorophyll
- GOGAT
ferredoxin-dependent glutamate synthase (EC 1.4.7.1)
- GS
glutamine synthetase (EC 6.3.1.2)
- MSX
l-methionine-d,l-sulfoximine
- NiR
nitrite reductase (EC 1.7.7.1)
- NR
nitrate reductase (EC 1.7.7.2)
- TP
total protein
This work has been partially supported by grants from the Spanish Ministry of Education and Science (DGICYT PB88-0300 and PB92-0464) and the University of the Basque Country (042.310-EC203/94). M.I.T. was the recipient of a fellowship from the Basque Government. 相似文献
7.
Ethanol was rapidly degraded to mainly acetate in anaerobic freshwater sediment slurries. Propionate was produced in small amounts. Desulfovibrio species were the dominant bacteria among the ethanol-degrading organisms. The propionate-producing Desulfobulbus propionicus came to the fore under iron-limited conditions in an ethanol-limited chemostat with excess sulfate inoculated with anaerobic intertidal freshwater sediment. In the absence of sulfate, ethanol was fermented by D. propionicus Lindhorst to propionate and acetate in a molar ratio of 2.0.l-Propanol was intermediately produced during the fermentation of ethanol. In the presence of H2 and CO2, ethanol was quantitatively converted to propionate. H2-plus sulfate-grown cells of D. propionicus Lindhorst were able to oxidize l-propanol and l-butanol to propionate and butyrate respectively with the concomitant reduction of acetate plus CO2 to propionate. Growth was also observed on acetate alone in the presence of H2 and CO2
D. propionicus was able to grow mixotrophically on H2 plus an organic compound. Finally, a brief discussion has been given of the ecological niche of D. propionicus in anaerobic freshwater sediments. 相似文献
8.
We describe the ability of carboxydotrophic bacteria for nitrate respiration or denitrification. Four out of fourteen strains examined could denitrify heterotrophically forming N2 (Pseudomonas carboxydoflava) or N2O (Pseudomonas carboxydohydrogena, Pseudomonas compransoris, and Pseudomonas gazotropha). Three carried out a heterotrophic nitrate respiration (Arthrobacter 11/x, Azomonas B1, and Azomonas C2). P. carboxydohydrogena could use H2 as electron donor for nitrate respiration under chemolithoautotrophic growth conditions. CO did not support denitrification or nitrate respiration of carboxydotrophic bacteria, although the free energy changes of the reactions would be sufficiently negative to allow growth. CO at 50 kPa was a weak inhibitor of N2O-reduction in carboxydotrophic and non-carboxydotrophic bacteria and decelerated denitrifying growth. Carboxydotrophic bacteria could utilize a wide range of N-sources. Results obtained with a plasmid-cured mutant of Pseudomonas carboxydovorans OM5 showed, that genes involved in nitrogen assimilation entirely reside on the chromosome. In the presence of an suitable electron donor, most carboxydotrophic bacteria could carry out a reduction of nitrate to nitrite that did not support growth and did not lead to the formation of ammonia.This article is dedicated to Professor Hans G. Schlegel on the occasion of his 65th birthday and in admiration for his élan and eternal idealism 相似文献
9.
The triphasic course previously reported for the reduction of cytochrome b in the succinate-cytochrome c reductase by either succinate or duroquinol has been shown to be dependent on the redox state of the enzyme preparation. Prior reduction with increasing concentrations of ascorbate leads to partial reduction of cytochrome c1, and a gradual decrease in the magnitude of the oxidation phase of cytochrome b. At an ascorbate concentration sufficient to reduce cytochrome c1 almost completely, the reduction of cytochrome b by either succinate or duroquinol becomes monophasic. Owing to the presence of a trace amount of cytochrome oxidase in the reductase preparation employed, the addition of cytochrome c makes electron flow from substrate to oxygen possible. Under such circumstances, the addition of a limited amount of either succinate or duroquinol leads to a multiphasic reduction and oxidation of cytochrome b. After the initial three phases as described previously, cytochrome b becomes oxidized before cytochrome c1 when the limited amount of added substrate is being used up. However, at the end of the reaction when cytochrome ca is being rapidly oxidized, cytochrome b becomes again reduced. The above observations support a cyclic scheme of electron flow in which the reduction of cytochrome b proceeds by two different routes and its oxidation controlled by the redox state of a component of the respiratory chain. 相似文献
10.
Cytochromes c
3 of different strains of sulfatereducing bacteria have been purified and tested for their capacity to reduce colloidal sulfur to hydrogen sulfide. The results are in good agreement with the activities reported for the whole cells. Cytochrome c
3 is the sulfur reductase of some strains of sulfate-reducing bacteria such as Desulfovibrio desulfuricans Norway 4 and sulfate-reducing bacterium strain 9974 from which the sulfur reductase activity can be purified with the cytochrome c
3. In contrast, Desulfovibrio vulgaris Hildenborough cytochrome c
3 is inhibited by the product of the reaction namely hydrogen sulfide. Chloramphenicol has no effect on the sulfur reductase activity of D. desulfuricans Norway 4 when resting cells grown on lactate-sulfate medium are put in the presence of colloidal sulfur. This shows that the sulfur reductase activity is constitutive and corresponds to the fact that colloidal sulfur grown cells do not contain more cytochrome c
3 (or another sulfur reductase) than lactate-sulfate-grown cells. 相似文献
11.
We studied the photosynthetic electron transfer system of membrane-bound and soluble cytochromec inChlorobium tepidum, a thermophilic green sulfur bacterium, using whole cells and membrane preparations. Sulfide and thiosulfate, physiological electron donors, enhanced flash-induced photo-oxidation ofc-type cytochromes in whole cells. In membranes,c-553 cytochromes with two (or three) heme groups served as immediate electron donors for photo-oxidized bacteriochlorophyll (P840) in the reaction center, and appeared to be closely associated with the reaction center complex. The membrane-bound cytochromec-553 had anE
m-value of 180 mV. When isolated soluble cytochromec-553, which has an apparent molecular weight of 10 kDa and seems to correspond to the cytochromec-555 inChlorobium limicola andChlorobium vibrioforme, was added to a membrane suspension, rapid photo-oxidation of both soluble and membrane-bound cytochromesc-553 was observed. The oxidation of soluble cytochromec-553 was inhibited by high salt concentrations. In whole cells, photo-oxidation was observed in the absence of exogenous electron donors and re-reduction was inhibited by stigmatellin, an inhibitor of the cytochromebc complex. These results suggest that the role of membrane-bound and soluble cytochromec inC. tepidum is similar to the role of cytochromec in the photosynthetic electron transfer system of purple bacteria. 相似文献
12.
Wytske de Vries H. G. D. Niekus Marian Boellaard A. H. Stouthamer 《Archives of microbiology》1980,124(2-3):221-227
Campylobacter sputorum subspecies bubulus was grown in continuous culture with excess of l-lactate or formate, and growth-limiting amounts of oxygen, fumarate, nitrate or nitrite. l-Lactate was oxidized to acetate, fumarate was reduced to succinate, and nitrate and nitrite were reduced to ammonia. The Y
lactate values (g dry weight bacteria/g mol lactate) for the respective hydrogen acceptors were much higher than the Y
formate values. Steady state cultures on formate and nitrite could only be obtained at a low dilution rate and low nitrite concentrations in the growth medium. In H+/2e measurements with lactate-grown cells proton ejections were observed with lactate or pyruvate as a hydrogen donor, and oxygen or hydrogen peroxide as a hydrogen acceptor. Proton ejection was also observed with pyruvate and nitrate. Proton ejection did not occur with lactate and nitrate, neither with lactate or pyruvate and fumarate or nitrite. With formate as a hydrogen donor acidification occurred with all hydrogen acceptors mentioned. It has been concluded that during growth on lactate and fumarate or nitrite substrate level phosphorylation at acetate formation is the sole ATP-generating system. Growth on formate and fumarate or nitrite is explained by a proton gradient generated as a result of oxidation of formate at the periplasmic side of the cytoplasmic membrane. With oxygen and nitrate additional ATP is formed by electron transport-linked phosphorylation. The low molar growth yields with formate are explained by the observation that formate-grown cells had a great permeability to protons.Abbreviations H+/2e value
number of protons ejected per electron pair transported in the respiratory system
- P/2e value
mol of ATP formed per electron pair transported in the respiratory system
- CCCP
carbonyl cyanide m-chlorophenyl-hydrazone 相似文献
13.
Jones C.E. Murphy P.J. Russell N.J. 《World journal of microbiology & biotechnology》2000,16(6):555-561
Six phenotypically distinct groups of bacteria were isolated from Spanish and Greek sources of alpeorujo, the waste from two-phase
decanter, continuous extraction olive oil mills. These different bacteria isolated from alpeorujo showed different growth
and osmoregulatory responses to conditions of reduced water activity (aw), and there was a correlation between the ability of isolates to withstand low aw and grow on alpeorujo. One isolate (1A), which grew particularly well both on alpeorujo and in nutrient broth containing
either 10% NaCl or 30% sucrose, was identified as being most closely related to Bacillus amyloliquifaciens using biochemical tests and partial 16S rDNA gene sequence analysis. Bacillus sp. strain 1A was found to display an atypical membrane lipid response at low aw since the major change was an increase in the zwitterionic phosphatidylethanolamine rather than an anionic phospholipid such
as phosphatidylglycerol. In addition, instead of the expected decrease, there was an increase in the average lipid fatty acid
acyl chain length at low aw without any other compensatory fluidizing change.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Balk M Weijma J Goorissen HP Ronteltap M Hansen TA Stams AJ 《Applied microbiology and biotechnology》2007,73(5):1203-1211
A sulfate-reducing bacterium, strain WW1, was isolated from a thermophilic bioreactor operated at 65°C with methanol as sole
energy source in the presence of sulfate. Growth of strain WW1 on methanol or acetate was inhibited at a sulfide concentration
of 200 mg l−1, while on H2/CO2, no apparent inhibition occurred up to a concentration of 500 mg l−1. When strain WW1 was co-cultured under the same conditions with the methanol-utilizing, non-sulfate-reducing bacteria, Thermotoga lettingae and Moorella mulderi, both originating from the same bioreactor, growth and sulfide formation were observed up to 430 mg l−1. These results indicated that in the co-cultures, a major part of the electron flow was directed from methanol via H2/CO2 to the reduction of sulfate to sulfide. Besides methanol, acetate, and hydrogen, strain WW1 was also able to use formate,
malate, fumarate, propionate, succinate, butyrate, ethanol, propanol, butanol, isobutanol, with concomitant reduction of sulfate
to sulfide. In the absence of sulfate, strain WW1 grew only on pyruvate and lactate. On the basis of 16S rRNA analysis, strain
WW1 was most closely related to Desulfotomaculum thermocisternum and Desulfotomaculum australicum. However, physiological properties of strain WW1 differed in some aspects from those of the two related bacteria. 相似文献
15.
Identification of a denitrifying bacterium and verification of its anaerobic ammonium oxidation ability 总被引:1,自引:0,他引:1
A strain D3 of denitrifying bacterium was isolated from an anammox reactor, and identified as Pseudomonas mendocina based on the morphological and physiological assay, Vitek test, Biolog test, (G+C) mol% content, and 16S rDNA phylogenetic
analysis. As a typical denitrifying bacterium, strain D3 achieved the maximal nitrate reduction rate of 26.2 mg/(L·d) at the nitrate concentration of 88.5 mg N/L. The optimal pH
and growth temperature were 7.84 and 34.9°C, respectively. Strain D3 was able to oxidize ammonia under anaerobic condition. The maximum nitrate and ammonium utilization rates were 6.37 mg/(L·d)
and 3.34 mg/(L·d), respectively, and the consumption ratio of ammonia to nitrate was 1:1.91. Electron microscopic observation
revealed peculiar cell in clusions in strain D3. Because of its relation to anammox activity, strain D3 was presumed to be anammoxosome. The present investigation proved that denitrifying bacteria have the anammox ability, and
the results have engorged the range of anammox populations. 相似文献
16.
Effect of nitrate and nitrite on sulfide production by two thermophilic,sulfate-reducing enrichments from an oil field in the North Sea 总被引:1,自引:0,他引:1
Kaster KM Grigoriyan A Jenneman G Jennneman G Voordouw G 《Applied microbiology and biotechnology》2007,75(1):195-203
Thermophilic sulfate-reducing bacteria (tSRB) can be major contributors to the production of H2S (souring) in oil reservoirs. Two tSRB enrichments from a North Sea oil field, NS-tSRB1 and NS-tSRB2, were obtained at 58°C
with acetate-propionate-butyrate and with lactate as the electron donor, respectively. Analysis by rDNA sequencing indicated
the presence of Thermodesulforhabdus norvegicus in NS-tSRB1 and of Archaeoglobus fulgidus in NS-tSRB2. Nitrate (10 mM) had no effect on H2S production by mid-log phase cultures of NS-tSRB1 and NS-tSRB2, whereas nitrite (0.25 mM or higher) inhibited sulfate reduction.
NS-tSRB1 did not recover from inhibition, whereas sulfate reduction activity of NS-tSRB2 recovered after 500 h. Nitrite was
also effective in souring inhibition and H2S removal in upflow bioreactors, whereas nitrate was similarly ineffective. Hence, nitrite may be preferable for souring prevention
in some high-temperature oil fields because it reacts directly with sulfide and provides long-lasting inhibition of sulfate
reduction. 相似文献
17.
A strain D3 of denitrifying bacterium was isolated from an anammox reactor,and identi-fied as Pseudomonas mendocina based on the morphological and physiological assay,Vitek test,Biolog test,(G C) mol% content,and 16S rDNA phylogenetic analysis.As a typical denitrifying bac-terium,strain D3 achieved the maximal nitrate reduction rate of 26.2 mg/(L·d) at the nitrate concen-tration of 88.5 mg N/L.The optimal pH and growth temperature were 7.84 and 34.9℃,respectively.Strain D3 was able to oxidize ammonia under anaerobic condition.The maximum nitrate and ammo-nium utilization rates were 6.37 mg/(L·d) and 3.34 mg/(L·d) ,respectively,and the consumption ratio of ammonia to nitrate was 1:1.91.Electron microscopic observation revealed peculiar cell inclusions in strain D3.Because of its relation to anammox activity,strain D3 was presumed to be anammoxosome.The present investigation proved that denitrifying bacteria have the anammox ability,and the results have engorged the range of anammox populations. 相似文献
18.
Green sulfur photosynthetic bacteria Chlorobium (Chl.) vibrioforme (DSM 263 strain and NCIB 8327 substrain possessing BChl-c) and Chl. tepidum (ATCC 49652) were photoautotrophically grown in liquid cultures containing different concentrations of sodium sulfide (Na2S). BChl-c homologs possessing a methyl group at the 12-position tended to increase in cells of the two strains of Chl. vibrioforme cultured under high Na2S concentrations. In contrast, the Na2S concentration in liquid cultures did not affect the relative composition of BChl-c homologs in Chl. tepidum. 8-Propyl-12-methyl([P,M])-BChl-c homolog, which has been little observed in usual cultivations, could be isolated by reverse-phase high-performance liquid chromatography from the cells of Chl. vibrioforme grown under high Na2S contents. The [P,M]-BChl-c homolog has the R-configuration at the 31-position, which was determined by 1H-NMR analyses. 相似文献
19.
Light inhibited each step of the denitrification process in whole cells of Rhodobacter sphaeroides forma sp. denitrificans. This inhibition by light was prevented in the presence of exogenous electron donors like N,N,N,N-tetramethyl-p-phenylenediamine (TMPD) plus ascorbate or in the presence of an uncoupler (carbonyl cyanide m-chlorophenylhydrazone). Addition of myxothiazol restored the inhibition by light in uncoupled cells. Measurements of light-induced absorbance changes under these conditions showed that this inhibition is due, for the steps of reduction of nitrite to dinitrogen, to the photooxidation of cytochromes c
1 plus c
2 and not due to the photoinduced membrane potential. Moreover, the presence of oxygen inhibited almost all of the reduction of nitrate and nitrous oxide but only 70% of the reduction of nitrite to nitrous oxide. These inhibitions were overcome in the presence of TMPD plus ascorbate. This implies that the inhibition in presence of oxygen was due to a diversion of the reducing power from the denitrifying chain to the respiratory chain. It was concluded from this series of experiments that the reduction of nitrate to nitrite is inhibited when the ubiquinone pool is partly oxidized and that nitrite and nitrous oxide reductions are inhibited when cytochromes c
1 plus c
2 are oxidized by photosynthesis or respiration.Abbreviations
R
Rhodobacter
- TMPD
N,N,N,N-tetramethyl-p-phenylenediamine
- HOQNO
2-n-heptyl-4-hydroxyquinoline N-oxide
- CCCP
carbonyl cyanide m-chlorophenylhydrazone
- cytochrome c
1
cytochrome c
2 plus cytochrome c
1 相似文献
20.
Carmelo Rigano Vittoria Di Martino Rigano Vincenza Vona Amodio Fuggi 《Archives of microbiology》1979,121(2):117-120
Addition ofl-methionine-dl-sulphoximine to cells ofCyanidium caldarium brings about a loss of glutamine synthetase activity. Concomitantly ammonia assimilation is prevented.Under physiological conditions nitrate reductase [NAD(P)H: nitrate oxidoreductase EC 1.6.6.2] is reversibly converted into an inactive enzyme upon addition of ammonia. In the presence of methionine sulphoximine, when glutamine synthetase activity is lost, nitrate reductase is no longer inactivated by ammonia. It is suggested that ammonia itself is not the actual effector of nitrate reductase inactivation.Concomitantly with the failure of nitrate reductase to undergo ammonia-inactivation, in the presence of methionine sulphoximine nitrate reduction is an uncontrolled process, thus, in media with nitrate ammonia continues to be produced and excreted into the external medium at a constant rate.Abbreviations NR
Nitrate reductase
- GS
Glutamine synthetase
- GOGAT
Glutamate syntase
- MSX
l-methionine-dl-sulphoximine 相似文献