Pseudomonas putida utilizes cyanide as the sole source of carbon and nitrogen. Agar, alginate, and carrageenan were screened as the encapsulating matrices for P. putida. Alginate-immobilized cells of P. putida degraded sodium cyanide (NaCN) more efficiently than non-immobilized cells or cells immobilized in agar or carrageenan. The end products of biodegradation of cyanide were identified as ammonia (NH3) and carbon dioxide (CO2). These products changed the medium pH. In bioreactors, the rate of cyanide degradation increased with an increase in the rate of aeration. Maximum utilization of cyanide was observed at 200 ml min-1 of aeration. Immobilized cells of P. putida degraded cyanides, cyanates and thiocyanates to NH3 and CO2. Use of Na[14C]-CN showed that 70% of carbon of Na[14C]-CN was converted into 14CO2 and only 10% was associated with the cell biomass. The substrate-dependent kinetics indicated that the Km and Vmax values of P. putida for the substrate, NaCN were 14 mM and 29 nmol of oxygen consumed mg protein-1 min-1 respectively.
A bacterium capable of utilizing either acetonitrile as the sole source of carbon and nitrogen or biphenyl as the sole source of carbon was isolated from soil and identified as Pseudomonas aeruginosa. The bacterium also utilized other nitriles, amides, and polychlorinated biphenyls (PCBs) as growth substrates. Acetonitrile- or biphenyl-grown cells oxidized these substrates without a lag. In studies with [14C]acetonitrile, nearly 74% of the carbon was recovered as 14CO2 and 8% was associated with the biomass. In studies with [14C]biphenyl, nearly 68% of the carbon was recovered as 14CO2 and nearly 6% was associated with the biomass. Although higher concentrations of acetonitrile as the sole sources of nitrogen inhibited the rates of [14C]biphenyl mineralization, lower concentrations (0.05%, w/v) gave a 77% stimulation in 14CO2 recovery. Pseudomonas aeruginosa metabolized acetonitrile to ammonia and acetic acid and biphenyl to benzoic acid. The bacterium also simultaneously utilized biphenyl as the sole carbon source and acetonitrile as the sole nitrogen source. However, biphenyl utilization increased only after the depletion of acetonitrile. Metabolites of the mixed substrate were ammonia and benzoic acid, which completely disappeared in the later stages of incubation. Nitrile hydratase and amidase were responsible for the transformation of acetonitrile to acetic acid and ammonia.
Male Sprague-Dawley rats were injected intraperitoneally with 0, 0.25, 0.75 and 1.25 mg/kg/day for 14 days. At the end of 7 and 14 days treatment period, body weight gain, serum protein, serum glucose, serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) were measured. Glucose-6-phosphatase (G6-Pase), fructose-1, 6-di-phosphatase (FD-Pase), phosphoenol pyruvate carboxykinase (PEPCK) and pyruvate carboxylase (PC) in kidney and liver were determined. A significant decrease in body weight gain in rats treated with 1.25 mg cadmium for 7 and 14 days was observed. Serum glucose, serum protein, SGOT and SGPT were increased in cadmium treated rats. A significant increase in all four key gluconeogenic enzymes were observed in both kidney and liver tissues of rats treated with cadmium. The results of this study suggest that cadmium induces gluconeogenesis which is dose and time dependent.
A bacterium capable of utilizing high concentrations of acetonitrile as the sole source of carbon and nitrogen was isolated from soil and identified as Pseudomonas putida. This bacterium could also utilize butyronitrile, glutaronitrile, isobutyronitrile, methacrylonitrile, propionitrile, succinonitrile, valeronitrile, and some of their corresponding amides, such as acetamide, butyramide, isobutyramide, methacrylamide, propionamide, and succinamide as growth substrates. Acetonitrile-grown cells oxidized acetonitrile with a Km of 40.61 mM. Mass balance studies with [14C]acetonitrile indicated that nearly 66% of carbon of acetonitrile was released as "4CO2 and 14% was associated with the biomass. Metabolites of acetonitrile in the culture medium were acetic acid and ammonia. The acetate formed in the early stages of growth completely disappeared in the later stages. Cell extracts of acetonitrile-grown cells contained activities corresponding to nitrile hydratase and amidase, which mediate the breakdown of actonitrile into acetic acid and ammonia. Both enzymes were intracellular and inducible and hydrolyzed a wide range of substrates. The specific activity of amidase was at least 150-fold higher than the activity of the enzyme nitrile hydratase.
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