The conversion of urea into ammonium carbonate with the ureaser of the soy bean has proven of value not only in urea determinations but in cases where urea interferes with some chemical manipulation since its removal can be readily accomplished by this enzyme.2 Data relative to the action and behavior of urease under various conditions should prove of value in many connections.3 In our original...

An improved sample preparation procedure for trace-levels of lanthanides in uranium-bearing samples was developed. The method involves a simple co-precipitation using Fe(III) carrier in ammonium carbonate medium to remove the uranium matrix. The procedure is an effective initial pre-concentration step for the subsequent extraction chromatographic separations. The applicability of the method was...

Uranyl acetate, a suppressor of victorin-induced electrolyte leakage in oat leaves when applied together with, or before, victorin, also suppressed victorin-induced changes in ultra-structure. Uranyl crystallized in cell walls and near the plasmalemma of vascular cells, but was excluded from the protoplasm. Fewer crystals occurred near the plasmalemma when leaves were allowed to take up uranyl ...

Bioreduction-based strategies for remediating uranium (U)-contaminated sediments face the challenge of maintaining the reduced status of U for long times. Because groundwater influxes continuously bring in oxidizing terminal electron acceptors (O2, NO3(-)), it is necessary to continue supplying organic carbon (OC) to maintain the reducing environment after U bioreduction is achieved. We tested ...

Bacteria have a great influence on the migration behaviour of heavy metals in the environment. Lipopolysaccharides form the main part of the outer membrane of Gram-negative bacteria. We investigated the interaction of the uranyl cation (UO2(2+)) with lipopolysaccharide (LPS) from Pseudomonas aeruginosa by using potentiometric titration and time-resolved laser-induced fluorescence spectroscopy (...

It has been commonly assumed that carbamate kinnse (EC 2.7.2.2, ATP : carbamate phospllotransferase) catalyzes the transfer of a phosphate group between 1TP and the carbamate ion. Evidence which has been put forward supporting this belief is the observation that freshly dissolved ammonium carbamate is a much better substrate for the enzyme than freshly dissolved ammonium carbonate at pH 9.4 (1)...