ABSTRACT
A radiochemical method has been adapted to determine (59)Ni and (63)Ni in samples of radioactive wastes from the water cleanup system of the IEA-R1 nuclear research reactor. The process includes extraction chromatographic resin with dimethylglyoxime (DMG) as a functional group. Activity concentrations of (59)Ni and (63)Ni were measured, respectively, by X-ray spectrometry and liquid scintillation counting, whereas the chemical yield was determined by ICP-OES. The average ratio of measured activity concentrations of (63)Ni and (59)Ni agree well with theory.
Subject(s)
Charcoal/chemistry , Ion Exchange Resins/chemistry , Nickel/analysis , Radioactive Waste/analysis , Radioisotopes/analysis , Radiometry/methods , Brazil , Charcoal/analysis , Ion Exchange Resins/analysis , Materials Testing/methods , Nickel/chemistry , Radiation Dosage , Radioisotopes/chemistryABSTRACT
AIMS: To investigate the diversity and the catabolic capacity of oil-degrading Klebsiella strains isolated from hydrocarbon-contaminated sediments in Santos-São Vicente estuary systems in Brazil. METHODS AND RESULTS: Klebsiella strains obtained from the estuary were characterized using 16S rRNA gene sequencing and BOX-PCR patterns, testing their catabolic capacity to degrade toluene, xylene, naphthalene and nonane, and identifying the catabolic genes present in the oil-degrading strains. Results show that Klebsiella strains were widespread in the estuary. Twenty-one isolates from the Klebsiella genus were obtained; 14 had unique BOX patterns and were further investigated. Among four distinct catabolic genes tested (todC1, ndoB, xylE and alkB1), only the todC1 gene could be amplified in two Klebsiella strains. The biodegradation assay showed that most of the strains had the ability to degrade all of the tested hydrocarbons; however, the strains displayed different efficiencies. CONCLUSIONS: The oil-degrading Klebsiella isolates obtained from the estuary were closely related to Klebsiella pneumoniae and Klebsiella ornithinolytica. The isolates demonstrated a substantial degree of catabolic plasticity for hydrocarbon degradation. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study show that several strains from the Klebsiella genus are able to degrade diverse hydrocarbon compounds. These findings indicate that Klebsiella spp. can be an important part of the oil-degrading microbial community in estuarine areas exposed to sewage.
Subject(s)
Hydrocarbons/metabolism , Klebsiella/isolation & purification , Soil Microbiology , Soil Pollutants/metabolism , Biodegradation, Environmental , Brazil , DNA Primers/genetics , DNA, Bacterial/analysis , DNA, Bacterial/genetics , Klebsiella/genetics , Klebsiella/metabolism , Naphthalenes/metabolism , Polymerase Chain Reaction , RNA, Ribosomal, 16S/genetics , Rivers/microbiology , Sequence Analysis, DNA , Toluene/metabolism , Xylenes/metabolismABSTRACT
[formula: see text] The first enantioselective total synthesis of a batzelladine alkaloid is described. The central reaction in the synthesis of (-)-batzelladine D (2) is a tethered Biginelli condensation of a guanidine aldehyde and an acetoacetic ester to generate a 7-substituted-1-iminohexahydropyrrolo-[1,2-c]pyrimidine intermediate having the anti stereochemistry of the methine hydrogens flanking the pyrrolidine nitrogen.
