著者

Ui Sadaharu Hosaka Takeshi Watanabe Kazuhide MIMURA AKlO

出版者

公益社団法人日本生物工学会

雑誌

Journal of fermentation and bioengineering (ISSN:0922338X)

巻号頁・発行日

vol.85, no.1, pp.79-83, 1998-01-25

被引用文献数

3

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A mechanism of 2, 3-butanediol(BD)stereoisomer formation was examined with respect to the BD cycle. The enzymes acetylacetoin synthase, acetylacetoin reductase(AACR), and acetylbutanediol hydrolse(ABDH), which are part of the BD cycle, were found to be present in the cell-free extract of the bacterial strain Bacillus cereus YUF-4, Two kinds of acetylbutanediol(ABD)stereoisomers were produced ill the reduction oF acetylacetoin(AAC)by AACR, which were identified as having 3R, 4R and 3S, 4R configurations by NMR spectroscopy and an enzymic method. The tyro ADD formations were found to be catalyzed independently by two respective enzymes: the former was catalyzed by a NADPH-dependent AACR(3R, 4R-ABD forming)and the latter by a NADH-dependent AACR(3S, 4R-ABD forming). The 3R, 4R-ABD was converted into R, R-BD and the 3S, 4R-ABD into R, S-BD by intracellular ABDH These findings demonstrated the existence of a new BD isomer formation mechanism derived from the BD cycle.

著者

Tomioka Noriko Tanaka Kaori Uchiyama Hiroo YAGI OSAMI KOKUFUTA ETSUO

出版者

公益社団法人日本生物工学会

雑誌

Journal of fermentation and bioengineering (ISSN:0922338X)

巻号頁・発行日

vol.85, no.6, pp.604-608, 1998-06-25

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With a bioaccumulation system using Rhodococcus erythropolis CS98 for recovery of cesium-137, we found that ^<137>Cs accumulated when a carbon source was added for energy supply. With the addition of ammonium acetate as the carbon source, almost all the ^<137>Cs from deionized water was recovered using a cell suspension of 1 g/l with incubation for 24h. Cell damage by radioactivity was not detected during the 24h period. ^<137>Cs recovery from river water samples was lower than that from deionized water, especially from river water with a very high potassium concentration(the lower reaches of the Sakura River : potassium concentration=4.3 mg/l). When 3.9 mg/l of potassium was added to a deionized water sample, ^<137>/Cs recovery decreased to 35% of that without potassium addition, suggesting that the potassium concentration is a critical factor for ^<137>Cs recovery. We conclude that a bioaccumulation system with a semipermeable membrane tube, such as is described in this paper, is feasible for the recovery of radioactive cesium from fresh waters.

著者

LARROCHE CHRISTIAN GROS JEAN-BERNARD

出版者

公益社団法人日本生物工学会

雑誌

Journal of fermentation and bioengineering (ISSN:0922338X)

巻号頁・発行日

vol.74, no.5, pp.305-311, 1992-11-25

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The growth and sporulation of Penicillium roquefortii were studied during solid state cultivations on support. The process involved the use of a porous material, pozzolano, impregnated and continuously fed at a small rate by a concentrated liquid nutritive medium. This system allowed the recovery of the total spores and biomass produced, due to the large average radius, close to 5 μm, of the pores available for the fungal development. The sporulation occurred in two waves, the first beginning when nitrogen limitation appeared. Nitrogen balances showed that this first wave occurred with a sporulation efficiency, defined as the ratio of the nitrogen incorporated into the conidia to the nitrogen assimilated by the mycelium, close to unity. The second wave gave spores that did not contain nitrogen. Carbon balances, established using the stoichiometric equations of the metabolisms that occurred, showed that this second sporulation wave arose in connection with assimilatory growth that took place together with mecelial lysis. This system allowed 7×10^8 active spores/g pozzolano to be obtained, corresponding to 4.7×10^<11> spores/l fermentor at 110 h cultivation.