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Studies on Saccharification from Alginate using Stenotrophomonas maltophilia
DuBok Choi,조훈,Beom-Young Ryu,Yu Lan Piao,최수경,Byung-Wook Jo,신운섭 한국공업화학회 2008 Journal of Industrial and Engineering Chemistry Vol.14 No.2
Various environmental factors affecting saccharification from alginate using Stenotrophomonas maltophilia were investigated in flask cultures. The cell concentrations increased from 0.6 to 0.92 optical density (OD) at 660 nm when the agitation rate increased from 15 to 90 rpm. On the other hand, the maximum concentration of sugar was obtained at 3.8 g/l after 4 days of culture at 15 rpm. After 3 days of preculture at 33 ℃, the sugar concentration peaked at 5.0 g/l after 5 days of culture. When 10 g/l of NaCl was used, the maximum concentration of sugar, 5.3 g/l, was obtained after 5 days of culture. Yeast extract and peptone were the best nitrogen source for effective saccharification. Especially, the sugar concentration was 6.1 g/l after 5 days of culture using a mixture of 1.0 g/l of yeast extract and 1.0 g/l of peptone. Under optimum conditions of culture and media, scale-up for effective saccharification from alginate was carried out in 5 l flasks. The cell concentration after 2 days of culture was 0.61 OD at 660 nm and showed no further increase after 3 days of culture. The sugar concentrations from alginate were increased with increasing culture time to 7.9 g/l after 9 days of culture.
Choi DuBok,Cha Wol-Suk,Kang Si-Hyung,Lee Byoung-Rai The Korean Society for Biotechnology and Bioengine 2004 Biotechnology and Bioprocess Engineering Vol.9 No.5
When SiHa cells were incubated for varying periods of time with extracts of PFF and PFM, the cytotoxicity of the ethanol extracts of PFF was higher than those of the other extracts. These results indicated that the extracts from fruiting bodies of p. ferulae contain antitumor Substances. When A549, SiHa and HeLa cells were incubated with different concentrations of PFF and PFM extracts, the ethanol extracts of PFF showed strong cytotoxicity against A549 tells at concentrations over $10{\mu}g/mL$ and against SiHa and HeLa cells at concentrations over $40{\mu}g/mL$. However, the differences in the cytotoxic effects of the hot water and ethanol extracts of PFM and the hot water extracts of PFF on all 3 cancer cells were not significant. Also, the PFF ethanol extracts induced synergistic effects on the TRAIL-induced apoptosis in A549 cells, which were strongly resistant to TRAIL. These results indicated that ethanol extracts of PFF were the most prominent antitumor agents toward lung cancer cells (A549).
Antioxidant Effect of Tea Tree Root Extracts using Various Extraction Methods
Choi, Hyun-suk,Lee, Myung-ja,Kwak, So-young,Choi, Dubok The Korean Society of Food and Nutrition 2022 韓國食品營養學會誌 Vol.35 No.5
To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.
Saccharification from Alginate using Pseudoalteromonas agarovorans
최두복(DUBOK CHOI),조훈(HOON CHO) 대한환경위생공학회 2008 대한환경위생공학회 정기총회 및 학술발표회 Vol.- No.-
For efficient saccharification of alginate, marine bacteria was isolated from seawater near the Korean south coast. Based on 16S rDNA sequence, the isolated strain was identified as Pseudoalteromonas agarovorans. Various environmental factors affecting saccharification of alginate using Pseudoalteromonas agarovorans CHO-12 have been investigated in flask cultures. The saccharification was found to be optimal at the temperature of 29℃ and pH of 8.0. Among various NaCl concentrations, the maximum sugar concentration was obtained at 13.8g/l when 30g/l of NaCl was used. However, when NaCl was below 10g/l, sugar concentration decreased remarkably. Yeast extract and CSL were the best nitrogen source for efficient saccharification. The maximum saccharification rate at 50l of reactor was obtained, 15 g/l after 2 day of culture, which was about 5.0 fold times higher than that of S. maltophilia.
최두복(DuBok Choi),조훈(Hoon Cho) 대한환경위생공학회 2009 대한환경위생공학회 정기총회 및 학술발표회 Vol.2009 No.-
This study was carried out to investigate effect or extraction process on the physico-chemical properties from seed oil of wild Camellia sinensis grown in Iksan. When methanol was used a extract solvent, the polyphenol compound concentration was highest, 424.7㎎/g, which was 2.5 fold higher than other solvents. Especially, when the methanol concentration was increased from 20 to 80%, the polyphenol concentration was relatively from 40 to 100%. The specific gravity and refractive index of green tea see oil (GTSO) were 0.92g/㎤ and 1.45, respectively. The chromaticities of light, red, and yellow in CRO were 88.6 and 98.7, respectively. Among various fatty acids, Oleic acid (C18:1) concentration was highest, 49.3% and Linoleic acid (C18:2) concentration was 25.8%. The degree of expediting rancidity of CRO was an order of Fe²?> Cu²?> Cr²?> Zn²?> Ni²?>. Especially, when Cu²?and Fe²? was used, the peroxide value concentration was about 4.0 fold higher than non addition of them. The inhibition effect of rancidity of GSTO using antioxidant with Cu²?and Fe²? was increased.