• 미생물학회지
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• 제29권5호
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• pp.307-313
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• 1991

A yellow-green, fluorescent siderophore A3 was extracellularly produced under iron-limited growth conditions from Pseudomonas synxantha A3. The physicochemical and biological properties of siderophore A3 were examined. The approxiamte molecular weights of the Fe(III)-siderophore A3-1 complex and Fe(III)-siderophore A3-2 complex were estimated to be about 1,300 and 1,100, respectively, by Bio-gel P2 gel exclusion chromatography. The molar ratio between the siderophore and the Fe(III)was 1.08 mole. The molecular weight of the complex could be calculated with this ratio and the new values were 1,150 and 960, respectively. The binding constant(K) between thesiderophore A3 and Fe(III) that determined by displacing the iron from the Fe(III)-siderophore complex with EDTA was 4.12*10$^{18}$ at pH 5.0. Siderophore A3 appeared to have antibacterial activity on several bacterial strains, however, ferric siderophore Ae complex did not show that activity. The cytotoxicity of siderophore A3 was obtained from Human Chronic Myelogenous Leudemia K562 cells. Inhibition concentration (50%)($IC_{50}$ ) was $0.17\mu$\{g/ml}.

• Journal of Microbiology and Biotechnology
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• 제12권6호
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• pp.979-985
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• 2002

The possibility of microalgal nitrogen treatment was tested in wastewaters with a low carbon/nitrogen (C/N) ratio. Chlorella kessleri was cultured in the two different artificial wastewaters with nitrate as a nitrogen source: one contained glucose for an organic carbon source and the other without organic carbon sources. The growth rates of the two cultures were almost identical when the aeration rate was over 1 vvm. These results suggest that microalgae could successfully remove nitrogen from wastewater, as far as the mass transfer of $CO_2$, was not limited. Nitrate was successfully reduced to below 2 mg $NO_3^-$-N/ml from the initial nitrate concentration of 140 mg $NO_3^-$-N/ml in 10 days, even in the wastewater with no organic carbon source. Similar results were obtained when ammonium was used as the sole nitrogen source instead of nitrate. Higher concentrations of nitrogen of 140, 280, 560 and 1,400 mg/ml were also tested and similar amounts of nitrogen were removed by algal cultures without showing any substrate inhibition.

• KSBB Journal
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• 제6권1호
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• pp.35-43
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• 1991

The production of poly-$\beta$-hydroxybutyrate(PHB) from methanol by batch and fed-batch cultivations of Methylobacterium sp. GL-10 was studied. PHB accumulation was stimulated by the nutrients deficiency including, NH4+, SO42-, and K+. The nitrogen deficiency was the most critical factor for PHB accumulation. In batch cultivation, the maximum cell concentration and PHB content were 1.86g/l and 0.62g/l, respectively, with 1.0%(v/v) of methanol and 0.5g/1 of ammonium sulfate. The mass doubling time of Methylobacterum sp. GL-10 was in the range of 4-5 hrs. The cell growth and PHB accumulation were severely inhibited at the methanol concentration over than 2% (v/v). To overcome methanol Inhibition, constant feeding and intermittent feedillg fed-batch cultivations were adopted, using C/N molar ratio as a control factor. In constant feeding fed-batch process, cell concentration was increased up to 2.67g/1, and PHB yield was enhanced from 0.33 of batch culture to 0.53. The relatively low cell concentration was caused by methanol accumulated in culture broth at late growth phase. To prevent methanol accumulation and to maximize PHB production, DO-state intermittent fed-batch cultivation was attempted. The cell and PHB concentration was reached up to 4.55g/1 and 1.80g/1, respectively. It was possible to maintain methanol concentration low and also to feed nutrient of desired C/N molar ratio.

• KSBB Journal
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• 제6권1호
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• pp.45-54
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• 1991

The aims of this study were investigated the antitumor effects and immunological activities of lipopolysaccharides (LPS) extracted from Proteus vulgaris RH-90 toward sarcoma-180 cells. LPS extracted from Proteus vulgris RH-90 was irradiated with gamma ray for detoxification. The tumor incidence of sarcoma-180 occurs all group which injected with gamma ray irradiated LPS and tumor of sarcoma-180 was necrotized with breeding in the injected group of l0$\mu\textrm{g}$ LPS. The inhibition ratio of tumor growth showed at the highest level of 60.88% when 5$\mu\textrm{g}$ gamma ray irradiated LPS was injected into mice. The prolongation ratio of life showed 20.72% when injected into mice with gamma ray irradiated LPS of 5$\mu\textrm{g}$. In the effect of immunological activity, the number of circurating leucocyte and peritoneal exudate cells were increased significantly in the treatment group than that control group, and dose-dependent response indicated by the increase of weights of immunorgans which revealed the improvement of immunity. The effect of macrophage on phagocytes, there were not found the differences between phagocytic and corrected phagocytic index.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.62-67
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• 2004

The biosynthesis of cephalexin was carried out in the aqueous two-phase systems using penicillin acylase as a catalyst, and 7-aminodeacetoxicephalosporanic acid (7-ADCA) and phenylglycine methyl ester (PGME) as substrates. 20% PEG400-l7.5% ${(NH_4)}_2SO_4$ containing 0.5 M NaCl and 1.5 M methanol aqueous two-phase systems (ATPS) were selected as reaction medium, and 53% product yield was obtained using immobilized penicillin acylase as a catalyst. 20% PEG400-l5% $MgSO_4$ ATPS was also used for the synthesis of cephalexin, and 60-62% product yield was obtained by using free penicillin acylase as a catalyst. When batch reactions were repeated in the ATPS, the cephalexin yields decreased during the reactions due to deactivation, loss, and product inhibition of penicillin acylase. The effect of different ratio of phenylglycine methyl ester to 7-ADCA on the product yield was investigated, and high cephalexin yield was obtained at a high molar ratio.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1995년도 춘계학술대회
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• pp.93-93
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• 1995

The three combined products were prepared as suspended solutions composed of various ratio of Sucralfate, Hydrotalcite and Neusilin, into which 30% ethanol extracts of Machili cortex, and of Atractylodis rhizoma were added. The efficacy for these products was examined in vivo using a pyrous ligation method in rats. The influence of these products on the intestinal motility was also examined in mice. In all experimental setting, the antisecretory effect of the combined treatment was more pronounced than that of each drug alone. The combined treatment consisted of Sucralfate, Hydrotalcite, Neusilin ratios of 2:2:1 produced the highest inhibitory effect for the gastric secretion. The intestinal motility was not influenced significantly by the treatment of all experimental setting. The above results revealed that the therapeutic dose of Sucralfate, Hydrotalcite, Neusilin given in combination showed a synergistic effect for the inhibition of gastric secretion and little side effect on the intestinal motility. Therefore, the combined product with Sucralfate, Hydrotalcite, Neusilin ratio of 2:2:1 is recommended for the useful drug to heal the gastrointestinal diseases with no side effect on the intestinal motility.

• Applied Biological Chemistry
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• 제39권4호
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• pp.293-296
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• 1996

니켈독성의 생물검정에 있어서 지표식물로 무를 이용하였고 수경재배 조건하에서 니켈용액의 농도에 따른 무종자의 발아율, 세포신장, ${\alpha}-amylase$ 활성도, 엽록소, 단백질함량을 조사한 결과 니켈처리농도를 증가시키면 종자의 발아초기에는 농도의존적으로 ${\alpha}-amylase$의 활성도가 크게 저해를 받기 시작하였으며, 발아후 생장단계에서는 엽록소 b와 a의 함량이 크게 저해를 받았다.

• Journal of Plant Biology
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• 제21권1_4호
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• pp.13-21
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• 1978

The effect of cyclic-AMP on the induction of acid phosphatase activity in barley aleurone layers was examined. Tannic acid was used as a inhibitor. Decursinol and coumarin were also used as a comparison. Maxiumu promotion of the enzyme activity was obtained with 10-5M cyclic-AMP, but this promotion was lower than that of 10-5M GAS induced enzyme activity in incubation medium. The inhibition rate in the addition of tannic acid was shown 17% and 63% at a ratio to GAs (by weight) of 10 : 1, and 58% and 94% at a ratio of 100 : 1 treated with GAs, and cyclic-AMP, respectively. The most potentiation of 10-6M GAS effect was induced by the additiion of suboptimal concentration (10-6M) of cyclic-AMP. Additional GAs and cyclic-AMP were shown the recovery of the enzyme activity inhibited by tannic acid. The combination with cyclic-AMP and theophylline enhanced the enzyme activity, too. Any other nucleotides tested except cyclic-AMP didn't show the action. There were no differences in acid phosphatase isozyme patterns by polyacrylamide disc electrophoresis, in conjunction with the different additions but the size of bands showed great differences. Especially, the 3rd band and the 5th band group were remarkable.

• Membrane and Water Treatment
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• 제10권4호
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• pp.265-275
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• 2019

This study aimed to develop a compact partial nitritation step by forming granules with high Ammonia-Oxidizing Bacteria (AOB) fraction using the Air-lift Granulation Reactor (AGR) and to evaluate the feasibility of treating reject water with high ammonium content by combination with the Anammox process. The partial nitritation using AGR was achieved at high nitrogen loading rate ($2.25{\pm}0.05kg\;N\;m-3\;d^{-1}$). The important factors for successful partial nitritation at high nitrogen loading rate were relatively high pH (7.5~8), resulting in high free ammonia concentration ($1{\sim}10mg\;FA\;L^{-1}$) and highly enriched AOB granules accounting for 25% of the total bacteria population in the reactor. After the establishment of stable partial nitritation, an effluent $NO_2{^-}-N/NH_4{^+}-N$ ratio of $1.2{\pm}0.05$ was achieved, which was then fed into the Anammox reactor. A high nitrogen removal rate of $2.0k\; N\;m^{-3}\;d^{-1}$ was successfully achieved in the Anammox reactor. By controlling the nitrogen loading rate at the partial nitritation using AGR, the influent concentration ratio ($NO_2{^-}-N/NH_4{^+}-N=1.2{\pm}0.05$) required for the Anammox was controlled, thereby minimizing the inhibition effect of residual nitrite.

• Journal of Ginseng Research
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• 제43권4호
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• pp.606-617
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• 2019

Background: The Panax ginseng berry extract (GBE) is well known to have an antidiabetic effect. The aim of this study is to evaluate and investigate the protective effect of ultrasonication-processed P. ginseng berry extract (UGBE) compared with GBE on liver fibrosis induced by mild bile duct ligation (MBDL) model in rats. After ultrasonication process, the composition ratio of ginsenoside in GBE was changed. The component ratio of ginsenosides Rh1, Rh4, Rg2, Rg3, Rk1, Rk3, and F4 in the extract was elevated. Methods: In this study, the protective effect of the newly developed UGBE was evaluated on hepatotoxicity and neuronal damage in MBDL model. Silymarin (150 mg/kg) was used for positive control. UGBE (100 mg/kg, 250 mg/kg, 500 mg/kg), GBE (250 mg/kg), and silymarin (150 mg/kg) were orally administered for 6 weeks after MBDL surgery. Results: The MBDL surgery induced severe hepatotoxicity that leads to liver inflammation in rats. Also, the serum ammonia level was increased by MBDL surgery. However, the liver dysfunction of MBDL surgery-operated rats was attenuated by UGBE treatment via myeloid differentiation factor 88-dependent Toll-like receptor 4 signaling pathways. Conclusion: UGBE has a protective effect on liver fibrosis induced by MBDL in rats through inhibition of the TLR4 signaling pathway in liver.