• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.167-171
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• 2000

Analysis of Production of Thermostable Alkaline Protease using Thermoactinomyces sp. E79. Jung, Sang Won, Sung-Sik Park, Yong-Cheol Park" Tae Kwang Oh2, and Jin-Ho Seo*, Department of Food Science and Technology, Seoul National University, Suwon 441-744, Korea, 1lnterdisciplinary program [or Biochemical Engineering & Biotechnology, Seoul National Univer5it}~ Seoul 151 "7421 Koreal 2Microbial Enzyme RU, Korea Research Institute of Bioscience & Biotechnology, Po. Box 1151 Yusong, Taejon 305"6001 Korea - This research was undertaken to analyze fermentation properties of Thermoactinomyces sp. E79 for production of a thermostable alkaline protease, which is able to specifically hydrolyze defatted soybean meal (DSM) to amino acids. TIle optimum pH for cell growth and protease production was pH 6.7, Thermoactinomyces sp. E79 did not grow at pHlO Among carbon sources tested, soluble starch was the best for protease production, while glucose repressed protease production. Tryptone was found to be the best nitrogen source for cell growth and soytone was good tor protease production. Oxygen transfer rate played an important role in producing thermostable alkaline protease. Ma'<..imum values of 6.58 glL of dry cell weight and 43.0 UJmL of protease activity were obtained in a batch fermentation using a 2.5 L jar fermentor at 1.93 X 102 hr-l of volumetric oxygen transfer coeff'jcient (kLa). Addition of 200 mgIL humic acid to the growth medium resulted in 1.64 times higher protease activity and 1.77 times higher cell growth than the case without humic acid addition.

• Journal of Dairy Science and Biotechnology
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• v.37 no.3
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• pp.196-205
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• 2019

Helianthus tuberosus is a perennial plant in the genus, Asteraceae. Pork potato has various pharmacological functions such as improving constipation, preventing bowel disease, inhibiting colon cancer, reducing serum cholesterol, lowering blood lipids, and enhancing blood sugar. This study investigated the physicochemical properties of fermented milk by adding Helianthus tuberosus powder. During the fermentation process, the pH of the fermented milk with added Helianthus tuberosus was higher after 16 hours of fermentation. At 48 hours of fermentation, the pH decreased to 3.70, 3.65, 3.63, and 3.59 with 0% (the control group), 1%, 3%, and 5% Helianthus tuberosus added, respectively. In the last 48 hours of fermentation, the acidity increased to 2.35%, 2.57%, and 3.17% with 0% (the control group), 1%, 3%, and 5% Helianthus tuberosus added, respectively. The number of lactic acid bacteria increased as the quantity of Helianthus tuberosus added increased. The highest number of lactic acid bacteria was 9.96 log CFU/g after 16 hours of fermentation with a 5% addition of Helianthus tuberosus . After 48 hours of fermentation, the amount of lactic acid bacteria decreased to 7.84 log CFU/g and 7.88 log CFU/g in the control group and the 1% added Helianthus tuberosus group, respectively. The addition of 3% and 5% Helianthus tuberosus increased the lactic acid bacteria count to 9.48 log CFU/ g and 9.81 log CFU/g, respectively. As the fermentation time increased, oxalic acid and tartaric acid decreased but lactic acid increased. Lactose degraded galactose and glucose over time. After 48 hours of fermentation, the viscosity in the control, 1%, 3%, 5% added Helianthus tuberosus groups increased to 1,006 cP, 1,026 cP, 1,040 cP, and 1,106 cP, respectively. The antioxidant effect was higher in the 5% added Helianthus tuberosus group (84.14%) than in the control group (80.39%) at 48 hours of fermentation. The concentration of polyphenol was 1.6 mg/g and antimicrobial activity was strong against E. coli and Staphylococcus aureus.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.599-607
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• 2015

Fermented-Rhus verniciflua (FRV) extract is increasingly used in fermented soy products, fermented vinegars, and certain alcoholic beverages. In this study, we investigated the effects of FRV extract on the physicochemical properties of doenjang (soybean paste). Addition of FRV extract to doenjang resulted in a 28.2-45.4% increase in the amino acid content and a 1.3- to 1.5-fold increase in the concentrations of glutamic acid, which imparts a savory flavor to doenjang. The concentration of biogenic amine (BA) of the sample containing the extract was 5.3-52.6% lower than that of the control. The major components of BA included tyramine (55.1-74.6%), followed by putrescine, spermidine, tryptamine, and cadaverine, in decreasing concentrations. The organic acid concentration of the sample containing the extract was 1.2-1.3-fold higher than that of the control. The total free sugar concentration was 163.4 mg/100 g in the control and 206.6-276.8 mg/100 g in the supplemented sample, showing a 1.3- to 1.9-fold increase as the addition of the extract.

• Journal of Environmental Science International
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• v.26 no.8
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• pp.967-976
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• 2017

In this study, the effect of probiotic supplementation on growth performance, blood metabolites, and meat quality of Hanwoo steer was investigated. A total of 32 Hanwoo steers (15-17 months, average body weight $462{\pm}37.9kg$) were randomly allotted to 4 dietary treatments (0, 0.5, 1.0, and 1.5% mixed probiotics), with four Hanwoo steers per pen (two replicates per treatments), and reared for 12 months. There were no differences among treatments in growth performance of Hanwoo steer (P>0.05); however, feed intake decreased linearly with increasing levels of mixed probiotics. Growth hormone and Blood Urea Nitrogen (BUN) levels responded linearly with increasing levels of dietary mixed probiotics (P<0.05), but not insulin and blood glucose did not. In particular, total cholesterol was significantly lower for the 1% mixed probiotic treatment in comparison with that of the other treatments (P<0.05). The pH, Thiobarbituric Acid Reactive Substances (TBARS), cooking loss, and meat color were influenced by increasing levels of mixed probiotics (P<0.05), but the carcass characteristics and shear force were not. Regarding sensory evaluation, the addition of mixed probiotics resulted in significant difference in meat color, tenderness, aroma, off-flavor, juiciness, and marbling score, but not in overall acceptability. In addition, fatty acid profiles indicated no differences between control and mixed probiotic treatments. In conclusion, mixed probiotic treatment at 1% levels can enhance consumer preferences possibly by reducing cholesterol and TBARS.

• Toxicological Research
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• v.15 no.1
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• pp.79-87
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• 1999

To know the stress response and antioxidative effect of sulfur containing compounds, we observed the expression of the stress protein (heat shock protein; inducible protein) from mouse tissues and evaluated the protective effects to hydroxyl radical in mouse brain cell culture. Cysteine, methionine or sodium sulfide was fed by oral administration of 1 ml/per 6hr/three times with 1 mM, 2mM or 3mM to mouse, respectively. After that, the stress proteins were extracted from mouse tissues and analyzed the features of expression. The stress proteins by sulfur containing compounds were showed different aspects in the kinds and concentrations of their compounds, and in the tissues of mouse. In the liver, the stress proteins were appeared at different time on the concentration of sulfur containing compounds and had less than 20 KDa as small molecules. In general, the molecular weights of stress protein in liver, the stress proteins were appeared at different time on the concentration of sulfur containing compounds and had less than 20 KDa as small molecules. In general, the molecular weights of stress protein in the spleen were evaluated from 32KDa to 50KDA, and the induced times were relatively late at high concentration of cysteine, early at low concentration of methionine or sodium sulfide. The stress proteins in mouse muscle were detected mostly between 24hr after treatment of sulfur containing compounds. Their molecular weights were 15~24KDa. In the antioxidative effects of sulfur containing compounds to hydroxyl radical, cell viabilities were measured by 63.2% at 10 $\mu\textrm{M}$, 65.5% at 50 $\mu\textrm{M}$, 68.6% at 100 $\mu\textrm{M}$, 78.3% at 150 $\mu\textrm{M}$, or 83.0% at 200 $\mu\textrm{M}$ of cysteine, respectively. At addition of methionine, the cell viabilities were assessed as 58.1% at 10 $\mu\textrm{M}$, 62.8% at 50 $\mu\textrm{M}$, 75.7% at 100 $\mu\textrm{M}$, 78.6% at 150 $\mu\textrm{M}$, and 79.2% at 200 $\mu\textrm{M}$ after 4hrs exposure with 20mU/ml glucose oxidase (GO) system, while the numbers of live cells to hydroxyl radicals in treatment of sodium sulfide were showed 48.6% at 10 $\mu\textrm{M}$, 54.8% at 100 $\mu\textrm{M}$, 51.8% at 150 $\mu\textrm{M}$, and 51.6% at 200 $\mu\textrm{M}$ in the neuronal cells. In the inhibitory effects on the proliferation of tumor cells, percentages of dead cells of the CT-26 or HeLa cell were generally less than 30% even 48hr after addition of sulfur containing compounds. Conclusively, the results of these experiments indicate that stress protein by sulfur containing compounds can be used as physiological indicator for animal nutrition and for environment, and also that cysteine and methionine can play critical roles as an antioxidant.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1403-1411
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• 2002

The aims of this study were, firstly, to analyze the biochemical compositions of serum and follicular fluid (FF) from prepubertal gilts after PMSG (1,000 IU) treatment. The concentrations of total proteins, lipids, cholesterol, glucose and sex hormones (progesterone, $P_4$; estradiol-$17{\beta}$, $E_2$; testosterone, T) were measured. Secondary, the effects of porcine FF (pFF) addition (40% and 100%) in IVM media and different culture conditions [Exp. 1: mBMOC-2+20% porcine serum (PS), fresh IVM medium, filtered IVMconditioned medium, or rabbit oviducts; Exp. 2: mBMOC-2+20%PS or stepwise medium replacement procedures (SMRP) cocultured with or without cumulus cells] on the in vitro development (IVD) of porcine oocytes were also examined. Results showed that no significant differences were found in total protein levels between serum and pFF from different sizes (large, >7 mm; medium, ~5-7 mm; small, <3-5 mm) of follicles (75-85 and 49-90 mg/dl; p>0.05). Total lipid concentrations remained constant in serum (395-472 mg/dl), and reduced significantly in the pFF from large follicles (287 mg/dl) at 132 h after PMSG treatment when compared to those at other time points (441-480 mg/dl). Basal cholesterol levels in serum and pFF at 12 h were similar (153-161 mg/dl), but increased at 36 h (186-197 mg/dl). Basal P4 and E2 levels in serum (0.1 ng/ml and 5.5 pg/ml) were low, but increased from 0.34 ng/ml and 12.13 pg/ml at 24 h to 0.81 ng/ml and 61.70 pg/ml at 98 h, respectively, after PMSG treatment (p<0.05). P4 levels increased linearly in pFF from large follicles during 12 through 132 h (138-1,288 ng/ml). A similar increase was also observed in $E_2$ levels (22-730 pg/ml) before 60 h post PMSG treatment, and then dropped afterwards (730-121 pg/ml). The development of the oocytes fertilized in 40% pFF-medium was greater than that in 100% pFF-medium group without gonaodtropin addition (31% vs 10%, p<0.05). However, both were lower than those in mBMOC-2+20%PS and in rabbit oviducts (p<0.05). When cocultured with cumulus cell monolayers, a greater cleavage rate was observed in the group cultured in filtered IVM-conditioned medium than the SMRP group (36% vs 18%, p<0.05). A similar phenomenon was also observed in the culture without cumulus cell monolayers (33% vs 19%, p<0.05). It is concluded that neither the fresh IVM nor filtered IVM-conditioned medium has positive effect on the IVD of oocytes. Coculture with cumulus cell monolayers and the SMRP were not beneficial to the development of IVF pig oocytes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.478-483
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• 1992

To evaluate a possible effects of instant buckwheat noodle on hepatic and serum lipids profiles, apparent digestibilities and growth rate, male young rats were fed diets containing sucrose as a control group, instant 100% wheat flour noodle, or instant wheat noodle fortified with either 10% or 30% buckwheat flour as experimental groups for 4 weeks. Weight gain and feed intake in the two buckwheat noodle fed groups were similar to those of the wheat flour fed groups. In addition, no significant differences were found in the apparent digestibilities among the groups experimented. There were no differences in the hepatic and serum cholesterol levels due to the diets. However, Buckwheat noodle group showed a trend to decrease the liver and serum concentration of triacylglycerol, compared to the sucrose and 100% wheat flour groups. The addition of buckwheat flour to wheat flour up to 30% seemed to be effective in lowering the hepatic triacylglycerol level. After 10hr fasting, the serum glucose level of the buckwheat noodle group was similar to the levels of the other groups. The presented results indicate that instant noodle containing buckwheat at the level of 30% has a mild hypotriglyceridemic effects, and no adverse effects on the digestion of macronutrients in rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1507-1514
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• 2008

Cholesterol oxidase catalyses the conversion of cholesterol to 4-cholesten-3-one. This enzyme has been used for clinical assay of human serum cholesterol and for reduction of cholesterol level in foods and feeds. In order to search the microorganism which has a high extracellular and stable activity of cholesterol oxidase, soil microorganisms were screened. As a result, the one with the highest extracellular cholesterol oxidase activity was obtained and named as the BEN 115. The BEN 115 strain was identified as one of the Nocardia species based on our taxonomic studies. The cholesterol oxidase from this strain was shown to have two bands of extracellular proteins on SDS-PAGE and Western blot. Their molecular masses were estimated to be about 55 and 57 kDa, respectively. In addition, this cholesterol oxidase was considerably stable at the broad range of pH $3.5{\sim}9.5$ and at the temperature of $25{\sim}55^{\circ}C$. The optimum pH and temperature of this cholesterol oxidase were pH 5.5 and $35^{\circ}C$, respectively. The activity of extracellular cholesterol oxidase could be enhanced 1.6 to 2.0 folds by the addition of nonionic detergent such as Triton X-114, Triton X-100, or Tween-80 into the culturing broth. The substrate specificities against campesterol, sitosterol and stigmasterol were measured to be 50%, 50%, and 27%, respectively, compared to the cholesterol. These results suggest that Nocardia sp. BEN 115 may be useful as a microbial source of cholesterol oxidase production.

• Ocean and Polar Research
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• v.25 no.3
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• pp.277-286
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• 2003

Nitrification performance of fixed film biofilters using coarse sand, loess bead, or styrofoam beads in biofilter columns 1 meter high and 30cm in diameter were studied at different hydraulic and organic matter loading rates. Synthetic wastewater was supplied to the culture tank in order to maintain desired TAN concentrations in inlet water to biofilters. All the biofilters were conditioned 5 months before start of sampling. TAN and $NO_2-N$ conversion rates increased with an increase in the hydraulic loading rate (HLR). However, the improvement in biofilter performance was not linearly correlated to HLR in styrofoam bead filters. This is mainly due to the characteristics of the styrofoam beads used. TAN conversion rates of sand filters increased with the increase of HLR up to $200m^3/m^2$. per day. No increase in the TAN conversion rate was observed at the highest HLR since flooding on the media surface took place. HLR had a significant impact on the TAN conversion rates in loess bead filter up to the highest HLR tested (P<0.05). TAN conversion rates were much less at organic matter loading rates of 9 and 18kg $O_2/m^3$ per day than those without the addition of organic matter in styrofoam bead filters. The addition of glucose resulted in a reduction of the TAN conversion rate from 540 to 284g $TAN/m^3$ per day. No significant difference of TAN conversion rates between the two organic matter loading rates was found (p<0.05). This indicates that the impact of organic matter on nitrification becomes less and less sensitive with an increase in the COD/TAN ratio. At an organic matter loading rate of 9kg $O_2/m^3$. per day, a great reduction of TAN conversion rates was observed in sand filters and loess bead filters. Clearly, organic matter can be one of the most Important Impacting factors on nitrification. $NO_2-N$ conversion rates showed a similar trend for TAN. Based on the TAN and nitrite conversion rates, styrofoam beads showed the best performance among the three filter media tested. Also, the low gravity and price of styrofoam beads make the handling easier and more cost-effective for commercial application. The results obtained at the highest organic matter loading rates can be used in the biofilter design in recirculating aquaculture system.

• Journal of the Korean Wood Science and Technology
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• v.27 no.2
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• pp.53-61
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• 1999

Effects of culture conditions and Mn(II) addition were investigated for production of extracellular manganese peroxidase by lignin-degrading fungus LSK-27, Nitrogen source was shown to more influence the production of extracellular manganese peroxidase by LSK-27 than carbon source. When peptone or yeast extract as nitrogen source was added, high MnP activity was obtained. Especially, nitrogen-sufficient culture condition was effective in MnP activity, showing significantly increase up to 1.0% peptone concentration, but carbon-sufficient was not. Mn(II) was shown to strongly induce the MnP production in culture fluids of LSK-27. Increase of MnP actiyity was obeserved up to addition of 100ppm Mn(II), and over this Mn(II) concentration appeared to be inhibitory. The highest level of MnP activity was attained when Mn(II) was added after 2 day incubation.