• 미생물학회지
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• 제11권3호
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• pp.109-114
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• 1973

It is well known that the ornithine-containing lipids were separated and identified from the other lipids of Rhodopseudomonas spheroides, Rhodospirillum, and Thiobacillus thiooxidans. An ornithine-containing lipid that lacks phosphorus and glycerol has been observed in Ferrobacillus ferrooxidans which was isolated from dalsung copper mine in Korea. The aminolipid was extracted from F.ferrooxidans and furthr purified by thin layer chromatography, and the product was identified as an ornithine-containing lipid by paper and liquid chromatography respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.422-427
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• 2003

Rhodopseudomonas palustris P4 can produce $H_2$ either from CO by water-gas shift reaction or from various sugars by anaerobic fermentation. Fermentative $H_2$ production by P4 is fast, but its yield is relatively low due to the formation of various organic acids. In order to increase $H_2$ production yield from glucose, P4 was investigated for the photo-fermentation of acetate which is a major by-product of fermentative $H_2$ production. Experiments were performed in batch modes using both light-grown and dark-grown cells. When the dark-grown P4 was challenged with light and acetate, $H_2$ was produced with the consumption of acetate after a lag period of 25 h. $H_2$ production was inhibited when a nitrogen source, especially ammonium, is present. When the dark-fermentation broth containing acetate was adopted for photo-fermentation with light-grown cells, $H_2$ production and concomitant acetate consumption occurred without a lag period. The $H_2$ yield was estimated as 2.4 - 2.8 mol $H_2/mol$ acetate and the specific $H_2$ production rate was as 9.8 ml $H_2/g$ cell${\cdot}$h, The fact that a single strain can perform both dark- and light-fermentation gives a great advantage in process development Compared to a one-step dark-fermentation, the combined dark- and light-fermentation can increase the $H_2$ production yield on glucose by two-fold.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.270-274
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• 2005

A reactor-scale hydrogen (H2) production via the water-gas shift reaction of carbon monoxide (CO) and water was studied using the purple nonsulfur bacterium, Rhodopseudomonas palustris P4. The experiment was conducted in a two-step process: an aerobic/chemoheterotrophic cell growth step and a subsequent anaerobic $H_2$ production step. Important parameters investigated included the agitation speed. inlet CO concentration and gas retention time. P4 showed a stable $H_2$ production capability with a maximum activity of 41 mmol $H_2$ g $cell^{-1}h^{-1}$ during the continuous reactor operation of 400 h. The maximal volumetric H2 production rate was estimated to be 41 mmol $H_2 L^{-1}h^{-1}$, which was about nine-fold and fifteen-fold higher than the rates reported for the photosynthetic bacteria Rhodospirillum rubrum and Rubrivivax gelatinosus, respectively. This is mainly attributed to the ability of P4 to grow to a high cell density with a high specific $H_2$ production activity. This study indicates that P4 has an outstanding potential for a continuous H2 production via the water-gas shift reaction once a proper bioreactor system that provides a high rate of gas-liquid mass transfer is developed.

• 한국식품과학회지
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• 제25권2호
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• pp.142-147
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• 1993

일광 에너지를 고정하고 식품공장의 폐수를 이용할 목적으로 56점의 분리원으로부터 광합성 세균 179주를 분리하고 그중 두부유청에서 제일 잘 자라는 균주를 선정하여 동정하고 두부유청을 기질로 하여 배양 최적조건을 조사하였다. 선정균주 B-Ps-106은 Rhodopseudomonas sphaeroides의 변종 또는 근연균으로 동정되었고 호기 배양보다 광혐기 배양에서 더 양호한 성장을 나타냈다. 최적 pH는 $8.5{\sim}9.0$이었고 최적온도는 $30^{\circ}C$ 이었고 최적광량은 $0.72\;ca1/cm^2/min$ 이상이었다. $K_2HPO_4$와 $(NH_4)_2SO_4$ 농도를 달리하여 각각 첨가한 결과 양쪽에서 모두 0.9 g/l 첨가했을 때 비교적 양호한 성장을 나타냈다.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.46-53
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• 1999

The purpose of this study was to optimize the conditions of continuous mixed culture of C.butyricum and R. spaeroides K-7, which were able to produce hydrogen using biomass-dreived substrate. To investigate the possibility of continuous culture, semi-continuous culture was carried out for 20 days. In semi-continuous culture using the reactor system, the replacement rate of fresh medium was 30% of total medium volume for the highest hydrogen evolution. In continuous culture, the optimum dilution rate was determined to be 0.05$h^{-1}$. The continuous culture produced 3.1 times as compared with the hydrogen on batch culture. On the other hand, the continuous mixed culture produced 1.3~2.1 times as much as hydrogen of the continuous monoculture of C. butyricum. When 10g of glucose in the media (1l) was supplied as a carbon source on continuous culture, mixed culture of C. butyricum and R. sphaeroides K-7 increased hydrogen evolution rate. Because considerable amount of glutamate was contained in waste water of glutamate fermentation, utilization of glutamate was examined in mixed culture. As a result of examination, production of hydorgen was slightly inhibited by high concentration of glutamate, more than 20mM, on continuous monoculture of R. sphaeroides K-7. On the other hand, both on continuous monoculture of C. butyricum and on mixed culture of C. butyricum and R. sphaeroides K-7, production of hydrogen was not inhibited by high concentration of glutamate such as 100mM. Hence this suggests that high concentration of waste water can be used as good substrate for hydrogen production on monoculture of C. butyricum and mixed culture of C. butyricum and R. sphaeroides K-7.

• Environmental Engineering Research
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• 제12권4호
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• pp.136-147
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• 2007

In an effort to identify possible microbes for seeking bioagents for remediation of herbicide-contaminated soils, seven species of phototrophic nonsulfur bacteria (Rhodobacter capsulatus and sphaeroides, Rhodospirillum rubrum, Rhodopseudomonas acidophila, blastica and viridis, Rhodomicrobium vannielii) were grown in the presence of the herbicide, butachlor, and bacterial growth rates and nitrogen fixation were measured with different carbon sources. Under general conditions, all species showed 17-53% reductions in growth rate following butachlor treatment. Under nitrogen-fixing conditions, Rb. capsulatus and Rs. rubrum showed 1-4% increases in the growth rates and 2-10% increases in nitrogen-fixing abilities, while the other 5 species showed decreases of 17-47% and 17-85%, respectively. The finding that Rp. acidophila, Rp. blastica, Rp. viridis and Rm. vannielii showed stronger inhibitions of nitrogenase activity seems to indicate that species in genera Rhodobacter and Rhodospirillum are less influenced by butachlor than those in Rhodopseudomonas and Rhodomicrobium in terms of nitrogen-fixing ability. Overall, nitrogenase activity was closely correlated with both growth rate and glutamine synthetase activity (representing nitrogen metabolism). When the carbon sources were compared, pyruvate (three carbons) was best for all species in terms of growth rate and nitrogen fixation, with malate (four carbons) showing intermediate values and ribose(five carbons) showing the lowest; these trends did not change in response to butachlor treatment. We verified that each of the 7 species had a plasmid ($12.2{\sim}23.5\;Kb$). We found that all 7 species could use butachlor as a sole carbon source and 3 species were controlled by plasmid-born genes, but it is doubtful whether plasmid-born genes were responsible to nitrogen fixation.

• Journal of Microbiology and Biotechnology
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• 제21권12호
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• pp.1306-1311
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• 2011

Recombinant Rhodopseudomonas palustris, harboring the carotenoid-metabolizing gene crtI (CrtIBS), and whose color changes from greenish yellow to red in response to inorganic As(III), was cultured in transparent microplate wells illuminated with a light emitting diode (LED) array. The cells were seen to grow better under near-infrared light, when compared with cells illuminated with blue or green LEDs. The absorbance ratio of 525 to 425 nm after cultivation for 24 h, which reflects red carotenoid accumulation, increased with an increase in As(III) concentrations. The detection limit of cultures illuminated with near-infrared LED was 5 ${\mu}g$/l, which was equivalent to that of cultures in test tubes illuminated with an incandescent lamp. A near-infrared LED array, in combination with a microplate, enabled the simultaneous handling of multiple cultures, including CrtIBS and a control strain, for normalization by the illumination of those with equal photon flux densities. Thus, the introduction of a near-infrared LED array to the assay is advantageous for the monitoring of arsenic in natural water samples that may contain a number of unknown factors and, therefore, need normalization of the reporter event.

• 한국양식학회지
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• 제7권3호
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• pp.135-150
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• 1994

은어의 효과적인 인공 종묘 생산을 위하여 자어의 성장과 생존율에 대한 먹이생물의 영양 가치에 대해 실험하여 다음과 같은 결과를 얻었다. 자어의 rotifer type에 따른 먹이효율을 조사하기 위해 3개 rotifer type (L-type, S-type, Us-type rotifer)을 각각 단독 또는 혼합하여 공급하였을 때 자어의 생존율은 모든 실험구에서 차이가 없었으나, 성장은 3 개 type rotifer를 모두 혼합하여 공급한 실험구에서 가장 높았다. Rotifer와 Artemia nauplius를 Chiorefla effipsoidea, 유지효모, 건조분말 Spimlina Platenis, Super Selco로 영양 강화시켜 자어에 공급한 영양 강화 실험에서 건조분말 S. platenis와 Super Selco를 혼합하여 영양 강화시킨 실험구에서 가장 높은 성장과 생존율을 보였다. Rotifer와 Arremia nauplius 공급시 자어의 사육 수조에 green water의 효과를 조사하기 위해 Chforefia ellipsoidea, 건조분말 Spimfina platensis, 광합성 세균(Rhodopseudomonas capsulatus)을 green water 원으로 사용하였을 때 건조분말 Sprinlina platenis와 광합성 세균을 혼합하여 공급한 실험구에서 가장 높은 성장과 생존율을 나타냈다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.594-597
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• 2001

RhodopseudolllOllas palustris P4 was studied for $H_2$ production from glucose in batch culture. Important conditions studied include phosphate concentration, initial pH, temperature, glucose concentration, and gas-phase replacement. Optimal $H_2$ production was observed at 60 - 300 mM of phosphate and 7.8 - 8.6 of initial pH. The effect of culture temperature was negligible When glucose concentration increased from 0.1 to 5% (w/v), $H_2$ production increased up to 2% and remained constant thereafter. Intermittent purging of the reaction botlle with Ar gas stimulated the Hl production by alleviating the inhibition by $H_2$. The maximum productivity was 111.1 ml $H_2$/h-1.

• 한국미생물·생명공학회지
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• 제24권6호
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• pp.738-742
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• 1996

An efficient packed-bed type biofilm reactor charged with immobilized phototrophs was developed to treat organic wastewater at an extremely high volumetric loading rate. The packed bed reactor (PBR) charged with porous ceramic beads was superior to a fluidized-bed reactor suspended with activated carbon powders in terms of many aspects such as BOD removal efficiency, operational stability, and overall economics. For wastewater with BOD concentration as high as 20, 000mg/l, the BOD removal efficiency was maintained above 90% when the hydraulic retention time (HRT) was longer than 1 day. The allowable volumetric BOD loading rate of this reactor (20gBOD/l day) is more than ten-folds higher than that of an ordinary activated sludge method. The behaviour of the reactor was represented well by a Monod type kinetic equation with a maximum specific BOD loading rate(P) of 22.2gBOD/l day and a half saturation constant(K$_{s}$) of 1, 750 mgBOD/l.