Asunto(s)
Bacterias/metabolismo , Cianuros/biosíntesis , Hongos/metabolismo , Aminoácido Oxidorreductasas/metabolismo , Chlorella/metabolismo , Chromobacterium/metabolismo , Cianuros/metabolismo , Eucariontes/metabolismo , Glicina/farmacología , Oximas/metabolismo , Peroxidasas/metabolismo , Fotosíntesis , Enfermedades de las Plantas , Pseudomonas/metabolismoRESUMEN
A metabolite of Trichoderma hamatum, 3-(3-isocyanocyclopent-2-enylidene)propionic acid, was tested for its effects on growth of and carbohydrate metabolism in 11 strains of functionally important rumen bacteria. To standardize the biological activity of this unstable metabolite, a rapid, aerobic disc diffusion assay was developed using Escherichia coli ATCC 11775. In an anaerobic broth dilution assay using a medium lacking rumen fluid and containing a soluble carbohydrate, the minimum inhibitory concentration of the metabolite which completely inhibited growth of the rumen bacteria for 18 h at 39 degrees C was generally less than 10 micrograms X mL-1; however, the minimum inhibitory concentrations for Megasphaera elsdenii B159 and Streptococcus bovis Pe(1)8 were 10-25 and 25-64 micrograms X mL-1, respectively. In general, the Gram-negative strains were more sensitive than the Gram positive. The minimum inhibitory concentration for Bacteroides ruminicola 23 grown with glucose was 1 micrograms X mL-1; for B. ruminicola GA33 (glucose), B. succinogenes S85 (cellobiose), and Succinivibrio dextrinosolvens 24 (maltose), it was 2 microgram X mL-1. When added to a cellulose-containing rumen fluid medium, 1-4 micrograms X mL-1 of the metabolite delayed cellulose hydrolysis by B. succinogenes S85, Ruminococcus albus 7, and R. flavefaciens FD1 for up to 4 days, and 6-7 micrograms X mL-1 prevented hydrolysis for at least 1 month. In the presence of the metabolite, the proportion of acetate produced from soluble carbohydrate by the majority of strains increased, but with some strains net production of acetate decreased relative to production of other acidic fermentation products.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Antiinfecciosos/aislamiento & purificación , Cianuros/aislamiento & purificación , Ciclopentanos/aislamiento & purificación , Hongos Mitospóricos/metabolismo , Nitrilos , Rumen/microbiología , Trichoderma/metabolismo , Animales , Antibacterianos , Bacterias/efectos de los fármacos , Bacterias/crecimiento & desarrollo , Cianuros/biosíntesis , Cianuros/farmacología , Ciclopentanos/biosíntesis , Ciclopentanos/farmacología , Cinética , Pruebas de Sensibilidad Microbiana , Especificidad de la EspecieAsunto(s)
Cianuros/metabolismo , Animales , Artrópodos/metabolismo , Bacterias/metabolismo , Compartimento Celular , Cianuros/biosíntesis , Eucariontes/metabolismo , Hongos/metabolismo , Glicósidos/metabolismo , Leucocitos/fisiología , Fagocitosis , Plantas/metabolismo , Ratas , Selenio/toxicidad , Tiosulfato Azufretransferasa/metabolismoRESUMEN
A cell-free preparation with cyanide-producing activity was obtained from a bacterium, strain C, of the genus Pseudomonas. To preserve activity, an oxidizing agent, e.g., phenazine methosulphage (PMS), had to be added to the cell suspension before disruption by sonic treatment. By the procedure described, a total homogenate made from a 15% (wet weight) bacterial suspension in tris(hydroxymethyl)aminomethane-hydrochloride buffer (0.05 M, pH 8.2) and with PMS (0.4mM) exhibited about 8% of the activity obtained from a suspension of untreated bacteria. In the presence of flavine-adenine dinucleotide (0.3 mM) and PMS (0.4mM), the activity was augmented to about 16% of that of the intact cells. By gradient centrifugation the homogenate was separated into three fractions. The main enzyme activity was associated with those fractions which by electron microscopy were found to consist of membranous structures.
Asunto(s)
Cianuros/biosíntesis , Glicina/metabolismo , Pseudomonas/metabolismo , Tampones (Química) , Fraccionamiento Celular , Sistema Libre de Células , Concentración de Iones de Hidrógeno , Microscopía Electrónica , NAD/metabolismo , Fenazinas/metabolismo , Fosfatos , Pseudomonas/ultraestructura , Sonicación , Fracciones Subcelulares/ultraestructura , Trometamina , UltracentrifugaciónAsunto(s)
Basidiomycota/metabolismo , Cianuros/análisis , Basidiomycota/crecimiento & desarrollo , Cromatografía en Papel , Frío , Medios de Cultivo , Cianuros/biosíntesis , Electroforesis en Papel , Glicósidos/análisis , Glicósidos/biosíntesis , Glioxilatos/análisis , Glioxilatos/biosíntesis , Espectroscopía de Resonancia Magnética , Piruvatos/análisis , Piruvatos/biosíntesis , SolventesRESUMEN
With whole cells of a hydrogen cyanide-producing bacterium strain C, of the genus Pseudomonas, it was found that the oxygen necessary for the oxidation of glycine to cyanide could be replaced by various artificial electron acceptors. The order of reactivity was: oxygen > phenazine methosulphate > methylene blue > 2,6-dichlorophenolindophenol > ferricyanide. Cyanide production was inhibited by pyrrolnitrin, a well-known inhibitor of many flavine enzymes. The molar ratio of added glycine to cyanide produced was found to be 1.09. With whole bacteria the apparent K(m) (glycine) for the cyanide production was found to be 5.0 x 10(-4) M.
Asunto(s)
Cianuros/biosíntesis , Glicina/metabolismo , Pseudomonas/metabolismo , Acridinas/farmacología , Anaerobiosis , Dióxido de Carbono/biosíntesis , Cobre/farmacología , Transporte de Electrón , Ferricianuros/metabolismo , Indofenol/metabolismo , Azul de Metileno/metabolismo , Oxidación-Reducción , Consumo de Oxígeno , Fenantrolinas/farmacología , Fenazinas/metabolismo , Pirroles/farmacología , SulfatosAsunto(s)
Basidiomycota/efectos de los fármacos , Fungicidas Industriales/farmacología , Compuestos Heterocíclicos/farmacología , Basidiomycota/enzimología , Basidiomycota/crecimiento & desarrollo , Basidiomycota/metabolismo , Catalasa/antagonistas & inhibidores , Catalasa/metabolismo , Catecol Oxidasa/antagonistas & inhibidores , Catecol Oxidasa/metabolismo , Cianuros/biosíntesis , Proteínas Fúngicas/biosíntesis , Oxatiinas/farmacología , Peroxidasas/antagonistas & inhibidores , Peroxidasas/metabolismo , TemperaturaAsunto(s)
Clorobencenos/metabolismo , Cianuros/biosíntesis , Nitrilos/metabolismo , Gases Lacrimógenos/metabolismo , Aerosoles , Animales , Antídotos , Compuestos de Bencilo/metabolismo , Compuestos de Bencilo/toxicidad , Clorobencenos/toxicidad , Cianuros/sangre , Ácido Edético/uso terapéutico , Masculino , Malonatos/metabolismo , Malonatos/toxicidad , Ratones , Ratones Endogámicos , Nitrilos/toxicidad , Nitritos/uso terapéutico , Intoxicación/prevención & control , Potasio , Sodio , Gases Lacrimógenos/toxicidad , Tiocianatos/orina , Tiosulfatos/uso terapéuticoRESUMEN
Cell-free extracts of Bacillus megaterium form beta-cyanoalanine (beta-CNA)-(14)C from Na(14)CN and l-cysteine, O-acetyl-l-serine or, to a lesser extent, l-serine. However, the presence of cyanide in the growth medium does not increase the capacity of cell extracts to catalyze the formation of beta-CNA from cysteine and cyanide. The formation of beta-CNA is readily detected in extracts of cells grown in synthetic media with sulfate or l-djenkolic acid as sulfur sources; such cells also exhibit an increased ability to form cysteine when compared with cells grown on cysteine as the sulfur source. beta-CNA formation could not be detected in extracts of cells grown on cysteine as the sulfur source. A 40-fold purification of the O-acetyl-serine sulfhydrylase resulted in the co-purification of the beta-CNA-forming activity. The sulfhydrylase and the beta-CNA-forming activity co-chromatographed on diethyl-aminoethyl cellulose and Sephadex G-100.
Asunto(s)
Alanina/biosíntesis , Bacillus megaterium/metabolismo , Cianuros/biosíntesis , Liasas/metabolismo , Acetatos , Sulfato de Amonio , Bacillus megaterium/enzimología , Bacillus megaterium/crecimiento & desarrollo , Isótopos de Carbono , Sistema Libre de Células , Precipitación Química , Cromatografía DEAE-Celulosa , Colorimetría , Medios de Cultivo , Cianuros/metabolismo , Cisteína/metabolismo , Liasas/aislamiento & purificación , Protaminas , Serina/metabolismo , Sulfatos/metabolismoAsunto(s)
Cianuros/biosíntesis , Sulfurtransferasas , Tiocianatos/metabolismo , Transferasas/metabolismo , Animales , Benzoatos , Compuestos de Bencilo , Carbamatos , Cloro , Cromatografía DEAE-Celulosa , Cromatografía en Gel , Cromatografía en Papel , Estabilidad de Medicamentos , Éteres , Glutatión , Calor , Moscas Domésticas/enzimología , Moscas Domésticas/metabolismo , Cianuro de Hidrógeno/síntesis química , Técnicas In Vitro , Insecticidas , Hígado/citología , Hígado/enzimología , Ratones , Microsomas Hepáticos/enzimología , Modelos Biológicos , Naftalenos , Nitrobencenos , Compuestos Organotiofosforados , Sulfurtransferasas/aislamiento & purificaciónAsunto(s)
Humor Acuoso/análisis , Vitamina B 12/administración & dosificación , Vitamina B 12/análisis , Anciano , Ambliopía/metabolismo , Humor Acuoso/metabolismo , Bioensayo , Extracción de Catarata , Cianuros/biosíntesis , Euglena , Humanos , Inyecciones Intramusculares , Persona de Mediana Edad , Retina/metabolismo , Vitamina B 12/sangre , Vitamina B 12/metabolismo , Cuerpo Vítreo/metabolismoAsunto(s)
Chromobacterium/metabolismo , Glicina/metabolismo , Cianuro de Hidrógeno/biosíntesis , Alanina/biosíntesis , Aminoácidos/biosíntesis , Aminoácidos/aislamiento & purificación , Isótopos de Carbono , Cianuros/biosíntesis , Cianuros/aislamiento & purificación , Glicina/aislamiento & purificación , Métodos , Nitrógeno/metabolismo , RadioisótoposRESUMEN
Nonproliferating cells of Chromobacterium violaceum incubated with glycine, methionine, and succinate as substrates accumulated beta-cyanoalanine in the culture fluid. Tracer experiments showed that carbons-2, -3, and -4 of beta-cyanoalanine are derived from the 2-carbon of glycine. When methionine-methyl-(14)C, succinate-1,4-(14)C, or succinate-2,3-(14)C was used as substrate, beta-cyanoalanine did not become labeled. If K(14)CN and serine were used as substrates, the cyano group of beta-cyanoalanine was labeled. Radioactive beta-cyanoalanine, labeled in the 3-carbon, was formed when glycine and H(14)CHO were used as substrates. (14)C-formic acid did not replace formaldehyde. Asparagine also accumulated in the incubated mixture and was found to be labeled in the amide carbon. Incubation of cells with beta-cyanoalanine-4-(14)C produced labeled aspartic acid in cell hydrolysates.
Asunto(s)
Alanina/biosíntesis , Chromobacterium/metabolismo , Cianuros/biosíntesis , Aminoácidos/análisis , Asparagina/biosíntesis , Ácido Aspártico/biosíntesis , Isótopos de Carbono , Formaldehído/metabolismo , Glicina/metabolismo , Metionina/metabolismo , Serina/metabolismo , Succinatos/metabolismoRESUMEN
An unidentified psychrophilic basidiomycete used valine and isoleucine as precursors to hydrocyanic acid (HCN). As probable intermediates in the pathway from valine and isoleucine two cyanogenic glucosides, linamarin and lotaustralin, were demonstrated in fungus cultures. The fungus contained two beta-glucosidases and an oxynitrilase which, acting together, were capable of releasing cyanide from both linamarin and lotaustralin. The two beta-glucosidases were purified and compared as to pH optimum, Michaelis constant, energy of activation, thermal stability, and substrate specificity. The products of methyl ethyl ketone cyanohydrin and acetone cyanohydrin dissociation by the oxynitrilase were demonstrated to be HCN together with methyl ethyl ketone and acetone, respectively. The oxynitrilase attacked aliphatic hydroxynitriles, but showed no activity on aromatic hydroxynitriles.