• Korean Journal of Microbiology
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• v.29 no.2
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• pp.130-135
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• 1991

The effects of a herbicide butachlor[2-chloro-2', 6'-diethyl-N-(butoxymethyl) acetanilide] on the growth of the purple non-sulfur bacteria were investigated. The butachlor inhibited the growth of all species tested by 18-51%, except Rhodospirillum rubrum at concentrations of M, which would be field capacity. The photosynthetic growth rate of the species in the presence of butachlor was influenced by the nitrogen source. Cultures supplied with (NH&S04 showed a somewhat higher growth rate than those fixing dinitrogen, but they were more susceptible to butachlor (26-51%). On the contrary, butachlor enhanced the growth rate of Rhodospirillum rubrum in nitrogen gas conditions. When the culture was performed in medium with butachlor as the carbon source, the cells of fixing dinitrogen showed a higher exhaustion of butachlor than those supplemented with (N&)2S04, which exhaustion was examined by a decrease of the major absorbance at 213 nm and 260 nm. The exhaustion of butachlor as the carbon source had relation with the growth of the cells. The alkalization of culture supplemented with nitrogen gas was found in the cells treated with butachlor or untreated. The butachlor affected the carotenoid region but bacteriochlorophyll remained unaffected.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.306-312
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• 2006

Disposal of food garbage in most large cities is very troublesome task. To date, microbiological treatment has been received an attention as a garbage decomposition process. In this study, the inoculation effect of some cellulase, amylase and protease-producing bacteria and photosynthetic bacteria on food garbage treatment was examined. They were added into a treatment reactor specially designed in this study together with food garbage and incubated in various conditions for 15 days and the removals of food garbage and foul smell produced during the treatment were analyzed. Average decomposition percentages of the inoculated food garbage in treatment reactor were 11 and 18.8% under intermittent aeration (once in a day) and continuous aeration conditions (2 L/min), respectively, and these were higher than removal percentages in the corresponding uninoculated reactors,3.4 and 13.8%. Optimal pH and temperature for food garbage decomposition by inoculated bacteria were pH 7.0 and $30^{\circ}C$. Maximal decomposition percentage in the inoculated food garbage was 35% under the optimal condition (pH 7, $30^{\circ}C$, and continuous aeration). The malodor compounds generated from food garbage treatment such as complex foul smell and sulfur compounds were effectively reduced about 84% and 25.5%, respectively, with a biofilter composed of purple nonsulfur bacteria trapped in sponge. This decomposing capability of food garbage by these bacteria can be utilized for the rapid and efficient treatment of food garbage.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.4
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• pp.315-323
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• 2005

The integrated or the two-stage (dark anaerobic and photosynthetic) fermentation processes were compared for the hydrogen production using purple non-sulfur photosynthetic bacteria, Rhodopseudomonas palustris P4. Cell growth, pH changes and organic acids and bacteriochlorophyll contents were monitored during the processes. Culture broth of Rps. palustris P4 exhibited dark-red during the photosynthetic culture condition, while yellow under the anaerobic condition without light. Rps. palustris P4 grown at the photosynthetic condition evolved 0.38 and 1.33 ml $H_2$/mg-dcw during the dark and the light fermentation, respectively, which were totally 1.71 ml $H_2$/mg-dcw at the two-stage fermentation. The rate of hydrogen production using Rps. palustris P4 grown under the dark anaerobic condition was 2.76 ml $H_2$/mg-dcw which consisted of 0.46 and 2.30 ml $H_2$/mg-dcw from the dark and the photosynthetic fermentation processes, respectively. Rps. palustris P4 grown under dark anaerobic conditions produced $H_2$ 1.6 times higher than that of grown under the photosynthetic condition. However, total fermentation period of the former was 1.5 times slower than that of the latter, because the induced time of hydrogen production during the photosynthetic fermentation was 96 and 24 hours when the seed culture was the dark anaerobic and photosynthetic, respectively. The integrated fermentation process by Rps. palustris P4 produced 0.52 ml $H_2$/mg-dcw(1.01 mol $H_2$/mol glucose), which was 20% of the two-stage fermentation.