Showing papers on "Cyanide published in 1983"

Method for Rapid Detection of Cyanogenic Bacteria

Abstract: An agar plate method is described in which the production of hydrogen cyanide by as many as 50 microbial isolates per plate may be detected. Cyanide produced by the organisms reacts with copper(II) ethylacetoacetate and 4,4'-methylenebis-(N,N-dimethylaniline) in a paper disk suspended above the microbial colonies. Cell growth occurs in depressions in the agar surface, which allows separation of colonies and enhances sensitivity of hydrogen cyanide detection.

Isolation and growth of a Pseudomonas species that utilizes cyanide as a source of nitrogen.

Abstract: SUMMARY: A simple method of isolating bacteria that utilize cyanide as a source of nitrogen for growth has been developed This involved supplying hydrogen cyanide as a vapour to glucose-containing minimal-salts agar plates The bacteria isolated were Gram-negative, oxidase-positive rods producing a fluorescent green pigment and were tentatively identified as strains of Pseudomonas fluorescens Three organisms were studied further and shown to be P fluorescens biotype II One of these (NCIB 11764) was grown in a glucose-containing fed-batch culture with either NH4Cl or KCN as the limiting nutrient Cyanide-grown bacteria produced stoichiometric amounts of ammonia from cyanide when pulsed with cyanide under aerobic conditions Stimulation of oxygen uptake was seen on addition of cyanide to suspensions of cyanide-grown but not ammonia-grown bacteria

Cyanide production by Pseudomonas fluorescens and Pseudomonas aeruginosa.

Abstract: Of 200 water isolates screened, five strains of Pseudomonas fluorescens and one strain of Pseudomonas aeruginosa were cyanogenic. Maximum cyanogenesis by two strains of P. fluorescens in a defined growth medium occurred at 25 to 30 degrees C over a pH range of 6.6 to 8.9. Cyanide production per cell was optimum at 300 mM phosphate. A linear relationship was observed between cyanogenesis and the log of iron concentration over a range of 3 to 300 microM. The maximum rate of cyanide production occurred during the transition from exponential to stationary growth phase. Radioactive tracer experiments with [1-14C]glycine and [2-14C]glycine demonstrated that the cyanide carbon originates from the number 2 carbon of glycine for both P. fluorescens and P. aeruginosa. Cyanide production was not observed in raw industrial wastewater or in sterile wastewater inoculated with pure cultures of cyanogenic Pseudomonas strains. Cyanide was produced when wastewater was amended by the addition of components of the defined growth medium.

Properties and Reconstitution of a Cytochrome Oxidase Deficient in Subunit III

Abstract: Three different preparations of beef heart cytochrome oxidase (EC 1.9.3.1) were reconstituted into the membranes of artificial liposomes, and the electrical charge/electron ratios were determined for charge translocation coupled to enzymic activity. Our previously characterised subunit-III-deficient preparation, which apparently lacks H+ translocation capacity [Saraste et al. (1981) Eur. J. Biochem. 115, 261-268] has a decreased charge/electron ratio (0.9-1.0) as determined from the uptake of potassium in the presence of valinomycin, in contrast to the intact reconstituted cytochrome oxidase (1.9-2.0). A third preparation that was depleted of three minor polypeptides by trypsin treatment (these polypeptides are also removed together with subunit III using the present method), but which retains subunit III, had a K+/e- ratio of 1.5 but also a relatively low respiratory control index. The pH-dependence of the Em of cytochrome a determined in the presence of cyanide is abolished in the subunit-III-deficient enzyme. Electron transfer activities are nearly identical for the original and subunit-III-depleted enzymes at an infinite concentration of cytochrome c in a polarographic assay with supplemented phospholipids. The optical spectral properties are very similar for both preparations, but with a small shift to the blue of the alpha-peak in the modified enzyme. These results support the hypothesis that the removal of subunit III abolishes the H+-translocating function of cytochrome oxidase. This occurs by an intrinsic decoupling of H+ transport from electron transfer, and yields a preparation with only half-maximal efficiency of energy conservation.

Carbon dioxide oxirane copolymers prepared using double metal cyanide complexes

Abstract: The invention is a process for the preparation of a carbon dioxide oxirane copolymer wherein the process comprises contacting carbon dioxide with an oxirane in the presence of (1) an organic coordination compound and (2) a catalytic amount of a double metal cyanide complex under conditions such that an oxirane carbon dioxide copolymer is prepared.

Cyanide as a feeding stimulant for the southern army worm, Spodoptera eridania

Abstract: . 1 All instars of Spodoptera eridania larvae grow as well or better when cyanide is present in their diet as when it is absent. Concentrations up to 0.05% stimulate feeding in first to fourth instar larvae. Concentrations from 0.1% to 1.0% stimulate feeding in fifth and sixth instar larvae. 2 Three-day-old sixth instar larvae pre-exposed to cyanide are completely resistant to its acutely toxic effects, but previously unexposed larvae suffer reversible symptoms of poisoning when feeding on a diet containing 1.0% KCN. 3 A 1.0% dietary KCN exposure during the sixth instar reduces ecdysis to 17% adult emergence and completely inhibits oviposition. 4 Cyanide concentrations from 0.5% to 1.0% in the diet, although effecting increased growth rates, induce necrotic lesions in larval mid-gut epithelial cells. 5 Thiocyanate, one of the in vivo cyanide metabolites, at 0.5% in the diet reduces pupation to 23%, delays and reduces adult emergence to 20% and inhibits oviposition. 6 The preferred host plant of S.eridania is the lima bean, Phaseolus lunatus, probably due to its content of the cyanogenic glycoside linamarin. Dietary valine has no effect on the southern armyworm feeding and growth behaviour (Long & Brattsten, 1982) but dietary cyanide does. The lima bean is known to contain up to 31 ppm cyanide in some varieties.

Hydrogen cyanide production by Pseudomonas aeruginosa at reduced oxygen levels.

Abstract: Hydrogen cyanide production by Pseudomonas aeruginosa growing in a synthetic medium required aerobosis but operated efficiently at low dissolved oxygen concentration. Half maximum levels of cyanogenesis occurred at 0.015 microM oxygen; maximum cyanogenesis occurred over a wide range, 0.1-180 microM, of oxygen concentrations. These cells lost the ability to produce cyanide upon aerobic incubation in the absence of both the carbon energy source (L-glutamate) and the metabolic precursor of hydrogen cyanide (glycine). This loss of cyanogenesis was dependent on oxygen concentration; 1.0 microM oxygen produced no detectable loss, whereas 180 microM oxygen caused a rapid decline in cyanogenic ability. The endogenous cyanide production rate of cells in the presence of carbon energy source was not significantly influenced by oxygen concentration. During the batch culture cycle, the acquisition of the ability to produce HCN was preceded by oxygen reduction to growth-limiting levels. Cells which had lost the ability to produce hydrogen cyanide by oxygen treatment required protein synthesis before they could again become cyanogenic.

Nitroprusside-induced formation of cyanide and its detoxication with thiosulfate during deliberate hypotension.

Abstract: Summary Infusion of sodium nitroprusside (SNP) leads to the formation of cyanide, which is potentially toxic for the patient. The extent of cyanide formation as a function of the SNP dose, and the protective effect of simultaneously administered thiosulfate were investigated in 55 patients in whom controlled hypotension was induced during surgery. 17 patients (group I) received less than 2 μg/kg/min of SNP, 14 patients (group II) 2–4 μg/kg/min, and 8 patients (group III) more than 4 μg/kg/min. In 8 cases (group IV), bolus injections of thiosulfate were given intermittently at hourly intervals. Eight patients (group V) were given an infusion of a mixture of SNP and thiosulfate (ratio by weight 1:8.3), which was administered with the aid of light-protected perfusing sets. The mean maximum cyanide concentrations in the red blood cells were 4.5 ± 1.1 nmol/ml for group I, 14.4 ± 2.9 nmol/ml for group II, and 48.2 ± 11.0 nmol/ml (mean ± SEM) for group III. In group I almost all the individual figures were less than 10 nmol/ml, in groups II and III the cyanide level increased with the rate of infusion and with the total dose (mg/kg). In group IV, the maximal cyanide levels were 13.0 ± 5.0 nmol/ml at a mean infusion rate of 4.79 ± 1.10 μg/kg/min. In group V, despite higher rates of infusion (5.56 ± 0.77 μg/kg/min), no cyanide levels in excess of 10 nmol/ml were found; the mean value was 5.7 ± 0.8 nmol/ml. These findings show that even with moderately long durations of administration (2–3 h), markedly elevated cyanide levels can result from SNP infusion rates in excess of 4–5 μg/kg/min. An infusion of a mixture of SNP and thiosulfate reliably prevents such SNP-induced increases in cyanide levels. If opaque perfusing sets are employed, such infusions can be carried out without any problems arising.

Structural and Functional Properties of Cytochrome c Oxidase from Bacillus subtilis W23

Abstract: The terminal component of the electron transport chain, cytochrome c oxidase (ferrocytochrome c: oxygen oxidoreductase) was purified from Bacillus subtilis W23. The enzyme was solubilized with alkyglucosides and purified to homogeneity by cytochrome c affinity chromatography. The enzyme showed absorption maxima at 414 nm and 598 nm in the oxidized form and at 443 nm and 601 nm in the reduced form. Upon reaction with carbon monoxide of the reduced purified enzyme the absorption maxima shifted to 431 nm and 598 nm. Sodium dodecylsulfate polyacrylamide gel electrophoresis indicated that the purified enzyme is composed out of three subunits with apparent molecular weights of 57 000, 37 000 and 21 000. This is the first report on a bacterial aa3-type oxidase containing three subunits. The functional properties of the enzyme are comparable with those of the other bacterial cytochrome c oxidases. The reaction catalyzed by this oxidase was strongly inhibited by cyanide, azide and monovalent salts. Furthermore a strong dependence of cytochrome c oxidase activity on negatively charged phospholipids was observed. Crossed immunoelectrophoresis experiments strongly indicated a transmembranal localization of cytochrome c oxidase.

The conversion of cyanide to ammonia by extracts of a strain of Pseudomonas fluorescens that utilizes cyanide as a source of nitrogen for growth

Abstract: Description des besoins des extraits cellulaires de Pseudomonas fluorescens pour la degradation du cyanure

Carbon monoxide-insensitive respiratory chain of Pseudomonas carboxydovorans.

Abstract: Experiments employing electron transport inhibitors, room- and low-temperature spectroscopy, and photochemical action spectra have led to a model for the respiratory chain of Pseudomonas carboxydovorans. The chain is branched at the level of b-type cytochromes or ubiquinone. One branch (heterotrophic branch) contained cytochromes b558, c, and a1; the second branch (autotrophic branch) allowed growth in the presence of CO and contained cytochromes b561 and o (b563). Electrons from the oxidation of organic substrates were predominantly channelled into the heterotrophic branch, whereas electrons derived from the oxidation of CO or H2 could use both branches. Tetramethyl-p-phenylenediamine was oxidized via cytochromes c and a exclusively. The heterotrophic branch was sensitive to antimycin A, CO, and micromolar concentrations of cyanide. The autotrophic branch was sensitive to 2-n-heptyl-4-hydroxyquinoline-N-oxide, insensitive to CO, and inhibited only by millimolar concentrations of cyanide. The functioning of cytochrome a1 as a terminal oxidase was established by photochemical action spectra. Reoxidation experiments established the functioning of cytochrome o as an alternative CO-insensitive terminal oxidase of the autotrophic branch.

Rapid Quantitation of Cyanide in Blood by Gas Chromatography

Abstract: A gas chromatographic method for the quantitative analysis of cyanide in blood has been developed. The analysis employs a headspace sampler and a nitrogen-phosphorus detector. The method is suitable for rapid, semi-automated quantitation when an auto-sampler and a data system are employed.

Metabolism of Acrylonitrile by Isolated Rat Hepatocytes

Abstract: Several of the pathways of metabolism of the suspected carcinogen acrylonitrile (AN) were identified previously in this laboratory with the use of subcellular fractions and purified enzymes (Guengerich, F. P., Geiger, L. E., Hogy, L. L., and Wright, P. L., Cancer Res., 41: 4925–4933, 1981). In order to establish the relative contributions of the various pathways leading to activated and detoxicated products, we examined AN metabolism in isolated Fischer 344 rat hepatocytes as a model. Reduced glutathione (GSH) was depleted, and cell viability was lost in an AN concentration-dependent manner. The major GSH adduct formed at all AN concentrations was identified as S -(2-cyanoethyl)GSH using thin-layer and high-performance liquid chromatography. Acid hydrolysis and amino acid analysis of labeled hepatocellular protein revealed S -(2-carboxyethyl)-cysteine as the major adduct formed, indicating direct alkylation of cysteinyl residues by AN. 2-Cyanoethylene oxide accumulated in the hepatocyte incubations but did not appear to contribute extensively to alkylation of GSH or protein. Cyanide, resulting from hydrolysis of 2-cyanoethylene oxide, appeared to be completely converted to thiocyanate, which was identified by gel exclusion chromatography and mass spectrometry of the methyl derivative. The concentration of thiocyanate formed was directly proportional to the concentration of AN used. Cyanide does not appear to play a role in AN-mediated cell death. Alkylation of hepatocellular DNA and RNA and extracellular DNA was not observed to an extent greater than one base in 3.5 × 105. The relative rates of the various pathways were compared, and more than 97% of the metabolites can be accounted for by the described reactions. These results are of use in evaluating the contribution of the various pathways and modes of binding of AN to toxicity and carcinogenicity in liver and extrahepatic target tissues.

Involvement of cytochromes and a flavoprotein in hydrogen oxidation in Rhizobium japonicum bacteroids.

Abstract: Electron transport components involved in H2 oxidation were studied in membranes from Rhizobium japonicum bacteroids Hydrogen oxidation in membranes was inhibited by antimycin A and 2-n-heptyl-4-hydroxyquinoline-N-oxide with Ki values of 394 and 56 microM, respectively The inhibition of H2 uptake by cyanide was triphasic with Ki values of 08, 99, and 936 microM This result suggested that three cyanide-reactive components were involved in H2 oxidation H2-reduced minus O2-oxidized absorption difference spectra showed peaks at 5515 and 560 nm, indicating the involvement of c- and b-type cytochromes, respectively This spectrum also revealed a trough at 455 nm, showing that H2 oxidation involves a flavoprotein This flavoprotein was not reduced by H2 in the presence of cyanide The inhibition of H2 or cytochrome c oxidation by the flavoprotein inhibitor Atebrin was monophasic; the Ki values were similar for both substrates A role for the flavoprotein as a terminal oxidase was implicated based on its high redox potential and its sensitivity to cyanide Cytochromes o and c-552 were identified based on their ability to bind carbon monoxide and cyanide

Cyanide exchange kinetics for planar tetracyanometalate complexes by carbon-13 NMR

Abstract: Etude faite sur Pd(CN) 4 2− , Pt(CN) 4 2− , Au(CN) 4 − et Ni(CN) 4 2− . Les vitesses sont dans l'ordre Ni>>Au>Pd>Pt

Steady-state kinetics of the catalase reaction in the presence of cyanide.

Abstract: Under carefully controlled experimental conditions, the Michaelis constant for H2O2 was measured to be 1.39 and 1.29 M in the reactions of beef erythrocyte and liver catalases, respectively. These values remained unchanged at temperatures between 1 and 26 degrees C. The turnover number of the Michaelis complex was about 2.25 X 10(7) s-1 for either enzyme at 26 degrees C. The cyanide inhibition in the catalase reaction has been reported to be noncompetitive in spite of the fact that cyanide and H2O2 compete for the same site on the catalase molecule. At high concentrations of H2O2, however, the inhibition became clearly competitive. The existence of the Michaelis complex and the anomalous features of cyanide inhibition were clearly accounted for on the basis of simple kinetic models. At H2O2 concentrations below 100 mM, the catalase reaction obeyed first order kinetics with respect to H2O2 and its apparent second order rate constant was measured to be 7.6 X 10(6) and 7.9 X 10(6) M-1 . S-1 for erythrocyte and liver catalases, respectively.

Low-spin ferric forms of cytochrome a3 in mixed-ligand and partially reduced cyanide-bound derivatives of cytochrome c oxidase.

Abstract: Optical-absorption-, e.p.r.- and m.c.d. (magnetic-circular-dichroism)-spectroscopic measurements were made on liganded derivatives of oxidized and partially reduced cytochrome c oxidase. When NO was added to oxidized cyanide-bound cytochrome c oxidase, no changes occurred in the optical-absorption difference spectrum. In contrast, NO induced reduction of cytochrome a3 and formation of the nitrosylferrohaem species when the oxidized resting enzyme was the starting material. E.p.r. spectroscopy of the NO-treated oxidized cyanide-bound enzyme revealed the presence of a low-spin haem signal at g = 3.40, whereas the g = 3.02 and g = 2.0 signals of the oxidized enzyme remained unchanged. Both haem groups in this species are e.p.r.-detectable simultaneously. Examination of an identical sample by m.c.d. spectroscopy in the near-i.r. region identified two distinct low-spin species at 1565 and 1785 nm. Irradiation with white light of the NO-treated cyanide-bound sample at 10K resulted in the disappearance of the g = 3.40 e.p.r. signal and the m.c.d. signal at 1785 nm, whereas a band at 1950nm increased in intensity. When the photolysed sample was warmed to 50K and held in the dark for 15 min, the original spectrum returned. Magnetization studies of the 1785nm m.c.d. band support the assignment of this signal to the same metal centre that gives rise to the g = 3.40 e.p.r. signal. The effect of NO on the oxidized cyanide-bound enzyme was compared with that obtained when the oxidized cyanide-bound species was taken to the partially reduced state. Cytochrome a3 is e.p.r.-detectable with a g-value of 3.58 [Johnson, Eglinton, Gooding, Greenwood & Thomson (1981) Biochem. J. 193, 699-708]. Its near-i.r. m.c.d. spectrum shifts from 1950nm in the oxidized cyanide-bound enzyme to 1545nm on addition of reductant. A scheme is advanced for the structure of the cytochrome a3-CuB site that allows for cyanide binding to Fea3 and NO binding to CuB. Cyanide is the bridging ligand in the ferromagnetically coupled cytochrome a3-CuB pair of oxidized cyanide-bound cytochrome c oxidase. The bridged structure and the magnetic interaction are broken when the enzyme is partially reduced. However, when NO binds to CuB the cyanide bridge remains intact, but now the odd spins of NO and CuB are magnetically coupled.

The acute lethal toxicity of mixtures of cyanide and ammonia to smolts of salmon, Salmo salar L. at low concentrations of dissolved oxygen

Abstract: The survival of Atlantic salmon smolts on exposure to constant concentrations of cyanide and ammonia, singly and together, has been measured under laboratory conditions at a concentration of 5 mgl-1 of carbon dioxide. The 24-h LC50 values of cyanide and of un-ionised ammonia, in fresh water, were 0·073 mg HCN l-1 and 0·20 mg NH3l-1 respectively at a concentration of dissolved oxygen of 10 mg l-1, and 0·024 mg HCN l-1 and 0·08 mgNH3l-1 respectively at a concentration of dissolved oxygen of 3·5 mg l-1. In 30% sea water the corresponding values were similar for cyanide but markedly higher for ammonioa. In 80% sea water the values were intermediate between those of fresh water and 30% sea water. Prior acclimation of the fish to the respective toxicant increased the resistance of the fish only slightly to cyanide, but with ammonia the 24-h LC50 was increased between 1·4 and 2-fold after acclimation for 1–3 days to between 0·2 and 0·5 of the 24-h LC50 value. Mixtures of cyanide and ammonia were between 0·6 and 1·25 times as toxic as expected, assuming simple additivity of toxicity.

Cyanide-induced cytochrome a,a3 oxidation-reduction responses in rat brain in vivo.

Abstract: The sensitivity of the brain to cyanide-induced histotoxic hypoxia and the protective effects of known cyanide antagonists, have been assessed in vivo by reflectance spectrophotometry. Cyanide-related changes in cytochrome a,a3 (cytochrome c oxidase) oxidation-reduction (redox) state, tissue hemoglobin saturation, and local blood volume were continuously monitored in cerebral cortex of rats. Noncumulative, dose-dependent inhibition of the in situ mitochondrial respiratory chain was evaluated directly by measuring increases in reduction levels of the terminal oxidase. These transient cytochrome a,a3 reductions were accompanied by increases in regional cerebral hemoglobin saturation and blood volume. Cytochrome redox responses were not altered either in magnitude or kinetics by hyperoxia; however, the cyanide-cytochrome dose-response curve was greatly shifted to the right by pretreatment with sodium nitrite, and the recovery rate of cytochrome a,a3 from cyanide-induced reduction was enhanced fourfold by pretreatment with sodium thiosulfate.

Determination of total cyanide in thiocyanate-containing wastewaters

Abstract: Utilisation d'EDTA, a pH 4, pour deplacer le cyanure des complexes metalliques et pour eviter la conversion de thiocyanate en cyanure libre quand des oxydants sont presents. Dosage spectrophotometrique du cyanure a l'aide de pyridine et d'acide barbiturique