In this study, we compiled a comprehensive dataset of hourly atmospheric 134 Cs and 137 Cs radioactivity concentrations in suspended particulate matter (SPM; aerosols less than 10 µm in diameter) that was systematically collected from March 12 to 23, 2011, in eastern Japan. In Japan, mass concentrations of SPM are measured using samples automatically collected on filter tapes at the air quality monitoring stations managed by the local governments. Most of the SPM monitoring stations in eastern Japan were operated during and/or after the Great East Japan Earthquake and tsunami that occurred on March 11, 2011, which triggered severe accidents at the Fukushima Daiichi nuclear power station (FDNPS). And the used filter tapes were sent to Tokyo Metropolitan University by the local governments through the Ministry of the Environment, Japan. The radionuclides in the hourly collected SPM samples at 99 of the more than 400 SPM stations were measured using Ge detectors. Because SPMs were collected hourly, the time series of the radiocesium concentration from March 12 to 23, 2011, has been described in detail. During this time, several radioactive plumes were observed in eastern Japan. Thus, precise description of these plumes (the peak time and the maximum radiocesium concentration in each plume at each SPM station) was our primary concern in this study. To confirm that our data were consistent with data independently measured by a research institution in Tokyo, we compared the hourly data by the institution with the hourly data for March 15-16 at an SPM station located near the institution. Although total suspended particulates were collected using a high-volume air sampler at the institution with a different sampling system, the data were highly consistent regarding the time series variations and radioactivity concentrations of 134 Cs and 137 Cs. This finding clearly indicates that the data presented in this study precisely reveal the 134 Cs and 137 Cs radioactivity concentrations in the atmosphere during March 2011. In addition to the radioactivity measurements, identifying the time and date when individual SPM samples were collected is equally important for producing a reliable database, and monthly reports of hourly SPM mass concentrations and SPM recording charts were used for confirmation. Cross-contamination is possible due to the apposition of radioactive materials from the SPM spot to the backside of the contacting tape. This cross-contamination is particularly likely for filter tapes made of polytetrafluoroethylene rather than glass fiber.

Escherichia coli trimethylamine N-oxide (TMAO) reductase I, the major enzyme among inducible TMAO reductases, was purified to homogeneity by an improved method including heat treatment, ammonium sulfate precipitation, and chromatographies on Bio-Gel A-1.5m, DEAE-cellulose, and Reactive blue-agarose. The molecular weight was estimated by gel filtration to be approximately 200,000. A single subunit peptide with a molecular weight of 95,000 was found by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This enzyme contained 1.96 atoms of molybdenum, 0.96 atoms of iron, 1.52 atoms of zinc, and less than 0.4 atoms of acid-labile sulfur per molecular weight of 200,000. The absorption spectrum of the enzyme showed a peak at 278 nm and a shoulder at 288 nm, but no characteristic absorption was found from 350 to 700 nm. A fluorescent derivative of molybdenum cofactor was found when the enzyme was boiled with iodine in acidic solution; its fluorescence spectra were almost the same as those of the form A derivative of molybdopterin found in sulfite oxidase. The molybdenum cofactor released from heated TMAO reductase I reconstituted nitrate reductase in the extracts of Neurospora crassa mutant strain nit-1 lacking molybdenum cofactor. Thus, TMAO reductase I contains molybdopterin, which is a common constituent of some molybdenum-containing enzymes. Some kinetic properties were also determined.

Sulfoacetaldehyde sulfo-lyase, which decomposes sulfoacetaldehyde to sulfite and acetate, was extracted from a bacterium grown on taurine, and purified, and characterized. A method for assay of enzyme activity was devised on formation of a bisulfite adduct with benzaldehyde. The enzyme was purified 14-fold from an extract of cells grown on taurine and appeared homogeneous on disc-electrophoresis. The molecular weight of the enzyme was estimated to be 85,000 by gel filtration. The enzyme required thiamine pyrophosphate (TPP) and Mg2+ for activity and preincubation with TPP and Mg2+ was required for maximum activity. The optimum pH for activity was 7.5. The Km value for TPP was determined to be 2.7 muM and that for sulfoacetaldehyde to be 5.0mM. Sulfite was produced only from sulfoacetaldehyde among a variety of sulfonates tested. rho-Chloromercuribenzoate, EDTA, and sulfite, a reaction product, inhibited the enzyme reaction. The enzyme seemed to be inducible, since activity was found in extracts of cells grown on taurine but not on peptone.

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[1] Boron, Cl, Ti, K, Sm, and Gd concentrations of oceanic crust samples were determined by prompt gamma neutron activation analysis. The samples include 63 basalts and 5 gabbros obtained at various depths

E. coli K10 was found to grow anaerobically on molecular hydrogen by reducing nitrate, fumarate, and trimethylamine N-oxide when peptone was added to the culture medium. Molar growth yields based on consumed hydrogen estimated from the amounts of reduction products were all 7.8 g cells/mol, suggesting that 1 mol of ATP was produced in the oxidation of 1 mol of hydrogen. Hydrogenase activity measured in terms of hydrogen evolution was several times higher in cells grown on glucose than in cells grown on hydrogen in the presence of fumarate and trimethylamine N-oxide, while hydrogenase activity measured in terms of hydrogen uptake was unchanged in both cases. The ratio of hydrogenase activities measured in terms of hydrogen uptake and evolution was also high in the extract and centrifugal fractions from cells grown in hydrogen. The soluble fraction and trypsin digest of the precipitate at 100,000 X g were subjected to polyacrylamide disc gel electrophoresis and hydrogenase bands were stained by reduction of benzyl viologen with hydrogen and by oxidation of reduced methyl viologen. The resulting patterns suggest that multiple forms of hydrogenase are present and that the amounts of forms functioning in hydrogen evolution were greatly decresed in cells grown on hydrogen in the presence of acceptors.

The complete primary structure of rubredoxin (Rd) isolated from Clostridium perfringens was sequenced to be: MKKFICDVCGYIYDPAVGDPDNGVEPGTEFKDIPDDWVCPLCGVDKSQFSETEE. The sequence was highly homologous to that of C. pasteurianum Rd but was different at 13 sites out of the total 54 amino acid residues (76% homology). It contained 1 Fe atom, 4 cysteine residues, and no labile sulfur, had a molecular weight of 6,056, and shared the general properties of classical anaerobic Rds. The pI was 4.4. The Rd was reduced with NADH in the presence of a specific NAD(P)H oxidoreductase preparation from the bacterium. The Km value of nitrate reductase for Rd as an electron-donor was 12 microM, a value comparable to that of the 13 microM for ferredoxin (Fd). These results taken together provide additional support for its role as the electron carrier in the nitrate reductase system [Seki, S., Ikeda, A., and Ishimoto, M. (1988) J. Biochem. 103, 583-584].

The enzymes in ammonia assimilation pathways have been examined in a strictly anaerobic bacterium Bacteroides fragilis. The activities of NADPH-and NADH-linked glutamate dehydrogenase and glutamine synthetase were demonstrated in extracts of cells, but very low activity of NADPH-dependent glutamate synthase and no activity of alanine dehydrogenase were demonstrated. Both activities of the glutamate dehydrogenase were not distinguished electrophoretically, indicating the presence of a dual pyridine nucleotide-specific enzyme. At low concentrations of ammonia in batch cultures and at low dilution rates of continuous flow cultures, higher activities of glutamate dehydrogenase were found in the cells. The values of Km of NADPH-linked glutamate dehydrogenase were 0.8 mM, 0.15 mM, and 7 uM for ammonia, 2-oxoglutarate, and NADPH, respectively. Although glutamine synthetase activity was also higher in cultures with limited ammonia and at low dilution rates of continuous cultures, this enzyme may not be important for ammonia incorporation into amino acids, since cell growth was not affected by the addition to the culture of methionine sulfoximine, a glutamine synthetase inhibitor. This evidence suggests that ammonia assimilation is mainly carried out by the glutamate dehydrogenase in B. fragilis.