• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1998.10a
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• pp.83-106
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• 1998

This study was conducted to investigate the probiotics(acid and bile resistance, fermentation properties, viability, cholesterol assimilation, antimicrobial activity, antimutagenicity, and immunoactivation) of the strains of bifidobacteria isolated from healthy Koreans and to investigate the effects of oral administration of Bifidobacterium longum A-2 on the fecal microflora, ${\beta}-glucuronidase$ activity, pH values, Ammonia concentration. The experimental results are summarized as follows: The probiotics were tested for 23 strains including three commer챠al strains as controls. Compared to other strains, strains of A-2 and A-9 showed more acid resistance whereas A-2, A-5, A-13, A-14, A-18 and A-22 showed excellent bile resistances. The properties of bifidobacteria during fermentation were tested. Strains of A-1, A-2, A-3, A-4, A-6, and A-23 resulted in less than pH 4.5 and titratable acidity over 0.90 after 24 hr of fermentation. When the strains of A-2 was grown with glucose, maltose, and fructooligosaccharide, the acetic acid production were higher than with sorbitol and mannitol. The storage stability of the strains of A-2 and A-22 were tesed, indicating the strain A-2 was more stable over 10 days of storage at both $4^{\circ}C$ and $20^{\circ}C$ than A-22. The strains of A-8, A-10, A-11, A-12 and A-20 assimilated more than 30% of cholesterol included in the media. The strains of A-1 and A-2 showed antimicrobial activity against Sta. aureus. The antimutagenicity of the strains were also tested, showing that the mutation was suppressed more by three strains(A-2, A-12, and A-23). In addition, strain A-5 improved immunological activity(phagocytosis, $TNF-{\alpha}$, IL-6) more than other strains. In the effects of oral administration of Bif. longum A-2, the number of fecal bifidobacteria was siginificantly increased(p<0.01) and the level of fecal ${\beta}-glucuronidase$ also was siginificantly reduced(p<0.05). However there were no siginificant differences in the level of Lαctobacilli, Enterobacteriaceae, Clostridium perfringens, pH and ammonia by the administration. The results suggested that Bif. longum A-2 may be met the criteria for probiotics culture.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.66-72
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• 2010

Pediococcus pentosaceus SA131 was isolated from jeotgal, is the bacteriocin producer against bovine mastitis pathogens, Streptococcus uberis E290, Enterococcus gallinarum E362, and Staphylococcus epidermidis ATCC 12228. The medium composition for pediocin SA131 production by P. pentosaceus SA131 was optimized using response surface methodology. Component of medium was studied as carbon source (glucose, fructose, lactose, glycerol, sucrose, maltose, and mannitol), nitrogen source (beef extract, yeast extract, peptone, malt extract, and tryptone), mineral and surfactant ($MgSO_4$, $KH_2PO_4$, $(NH_4)_2SO_4$, $MnSO_4$, NaCl, sodium acetate, and Tween 80). Through one factor-at-a-time experiment, glucose, fructose, yeast extract, malt extract, NaCl, $MgSO_4$, and Tween 80 were determined as the good ingredient. The effects of major factors for pediocin SA131 production were investigated by two-level fractional factorial designs (FFD). By a $2^4$ FFD, fructose, yeast extract, and $MnSO_4$ were found to be the important factors for the bacteriocin production. Subsequently, a $2^3$ central composite design (CCD) was adopted to derive a statistical model for optimizing the composition of the fermentation medium. The estimated optimum composition for the production of pediocin SA131 by P. pentosaceus SA131 was as follows; 0.13% fructose, 1% glucose, 1.8% yeast extract, 2.58% $MnSO_4$, 0.2% NaCl, and 0.2% Tween 80. The pediocin production under optimized medium was increased to 1,000 AU/mL, compared to the 400 AU/mL in MRS medium.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.1
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• pp.143-151
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• 2001

A marine bacterium producing carotenoid was isolated from the Yosu coastal area of South Korea, which was recorded as MCK-1. It was identified as Erythrobacter sp. Optimium conditions of marine carotenoid fermentation from Erythrobacter sp. were pH 6.0, a temperature of $25^{\circ}C$, 16 mM mannitol as a carbon source, 0.5% tryptone as a nitrogen source, 0.1 mM $Fe^{+2}$ ion as a mineral source and 1$\mu$M of cyanocobalamine as a growth factor in a jar-fermentor. Erythrobacter sp. was produced 351.27 mg/100mL of the marine carotenoid in these optimum conditions. This marine carotenoid was composed of 4 different conpounds, like as notoxanthin (61.4%), can thaxanthin (24.6%), fucoxanthin (8.2%), and zeaxanthin (5.8%). Physiological properties including antibacterial activity, cytotoxic effect, antioxidative effect and free radical scavenging activity were characterized with crude carotenoid. Carotenoid exhibited no antibacterial activity against E. coli and lactobacillus bulgaricus, but showed cytotoxic effect against cancer cells such as HepG2 (Hepatocellular carcinoma, human, ATCC HB-8065) and HeLa (Cervical carcinoma, human, ATCC CCL-2) cells. The impediment ratios for HepG2 and HeLa cell were 37.14% and 33.78%, respectively. This carotenoid expressed a strong antioxidative effect (77%) against CCL-13 5 $\mu\textrm{g}$/mL and 50 $\mu\textrm{g}$/mL crude carotenoid, respectively.

• The Journal of the Korean Society for Microbiology
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• v.10 no.1
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• pp.25-32
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• 1975

The majority of Nocardial infections reported in North America areIN. ;asteroides while those in Latin America are N. brasiliensis species. Infection with N. brasiliensis, to our knowledge, has not previously been reported in Korea. The auther isolated one strain of Nocardia brasiliensis from the abscess of right bottock of 23 month old female leukemic patient who was treated with methotrixate for five months at the Seoul National University Hospital. The morphological characteristics and biological properties were similar with the R.E. Gordon's description. The results are summarized as follow: 1. After 5 days incubation on Sabouroud's glucose agar, the acid fast character appeared partially. 2. Tyrosine, casein and urea were decomposed by 7 days incubation both at room temperature and at $37^{\circ}C$. 3. Sod, citrate and sod. acetate were utilized at $22^{\circ}C\;and\;37^{\circ}C$ after 28 days incubation while the sod. benzoate utilization was negative. 4. The survival range of temperature was from $10^{\circ}C\;to\;40^{\circ}C$. 5. Dulcitol, galactose, glycerol, lactose, maltose, mannitol, raffinose, rhamnose, sorbitol, trehalose and xylose fermentations were not observed up to 28 days, while the fermentation of glucose and inositol were positive.

• Korean Journal of Veterinary Service
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• v.26 no.2
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• pp.121-128
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• 2003

This study was carried out to identify and investigate antimicrobial susceptibility for Mannheimuia haemolytical which is responsible for shipping fever. Samples were collected from nasal and lung of 100 adult healthy cattle which are slaughtered in Samsung meat corporation located in Incheon metropolitan city. lung lesion index have been investigated within 0-5 range according to Shewen and Willkie(Can J Vet Res 52:30-36, 1988). Eighty-seven of 100 cattle were under normal condition with 0-1 ranges. A total of 129 strains were collected from blood and tryptic soy agar. Among these strains, 100 strains were identified with Staphylococcus, Streptococcus and enterobacteria containing E coli. Biochemical and fermentation assay of arabinose, trehalose, xylose, mannose, mannitol, lactose and salicin were tested to identify with Mannheimia sp. for 7 strains shown haemolytic activity on blood agar. Five strains were identified with Mannheimia haemolytica and 2 strains were untyped. In seasonal survey, Mannheimia sp recovered from fall to winter(5 of 7) have been highly isolated rather than those from spring to summer(2 of 7). Mannheimiz haemolytica were susceptible to antibacterials tested in this study but more resistant to oxytetracycline and streptomycin.

• Journal of Microbiology and Biotechnology
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• v.26 no.11
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• pp.1891-1907
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• 2016

Yeasts that are present in marine environments have evolved to survive hostile environments that are characterized by high exogenous salt content, high concentrations of inhibitory compounds, and low soluble carbon and nitrogen levels. Therefore, yeasts isolated from marine environments could have interesting characteristics for industrial applications. However, the application of marine yeast in research or industry is currently very limited owing to the lack of a suitable isolation method. Current methods for isolation suffer from fungal interference and/or low number of yeast isolates. In this paper, an efficient and non-laborious isolation method has been developed and successfully isolated large numbers of yeasts without bacterial or fungal growth. The new method includes a three-cycle enrichment step followed by an isolation step and a confirmation step. Using this method, 116 marine yeast strains were isolated from 14 marine samples collected in the UK, Egypt, and the USA. These strains were further evaluated for the utilization of fermentable sugars (glucose, xylose, mannitol, and galactose) using a phenotypic microarray assay. Seventeen strains with higher sugar utilization capacity than the reference terrestrial yeast Saccharomyces cerevisiae NCYC 2592 were selected for identification by sequencing of the ITS and D1/D2 domains. These strains belonged to six species: S. cerevisiae, Candida tropicalis, Candida viswanathii, Wickerhamomyces anomalus, Candida glabrata, and Pichia kudriavzevii. The ability of these strains for improved sugar utilization using seawater-based media was confirmed and, therefore, they could potentially be utilized in fermentations using marine biomass in seawater media, particularly for the production of bioethanol and other biochemical products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.163-171
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• 1980

Recently, Bacillus has been identified as one of food poisoning bacteria especially in products of cereal foods in foreign countries. Therefore, the quantitative distribution of Bacillus cereus in market foods, its physiological characteristics, growth rate by temperature and heat resistance of its spore were examined. Thirty two samples of cooked rice, 20 samples of kimbab(cooked rice rolled with laver), 23 samples of rice cake, 13 samples of rice ana 13 samples of barley were collected from restaurents and food stores in Busan, Korea during the period from May to November in 1980. Forty samples of 101 samples submitted to the test appeared positive for Bacillus cereus showing abut $40\%$ in detection ratio. Detection ratio of Bacillus cereus was higher than $50\%$ in barley and rice, and about $30\%$ in rice products. Average Bacillus cereus content of in the samples was $2.6\times10^6/g$ in cooked rice, $2.3\times10^6/g$in kimbab, $4.9\times10^4/g$ in rice cake while that in rice and barley was about $10^3/g$. The result of biochemical tests of the bacterium was $100\%$ positive in catalase, egg yolk reaction, gelatin hydrolysis and glucose fermentation, $100\%$ negative in xylose, arabinose and mannitol oxidation, about $90\%$ positive in acetoin production, $80.0\%$ positive in nitrate reduction and citrate utilization and $55.0\%$ positive in starch hydrolysis test. Isolation ratio of Bacillus ceresus which showed haemolysis positive and starch hydrolysis negative results, was about $38\%$ in 40 strains examined. It is known that those strains has a close relation to food poisoning accident. Growth rate and generation time of Bacillus cereus isolated from the cooked rice were $0.34hr^{-1},\;2.02hr\;at\;20^{\circ}C,\;0.73hr^{-1},\;0.95hr\;at\;30^{\circ}C\;and\;0.49hr^{-1},\;1.44\;hr\;at\;40^{\circ}C$ respectively. Heat resistance value of Bacillus cereus spores suspended in phosphate buffer solution was $D_{90}=29.0min,\;D_{95}=8.7min,\;D_{98}=3.7\;min\;and\;D_{101}=2.3\;min(z=10.5)$.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.90-94
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• 2013

A new Bacillus strain designated as MP56 producing antimicrobial substance has been isolated from the mud flat of Korea. The strain MP56 was found to exhibit broad spectrum of antimicrobial activity against Gram-positive pathogenic microorganisms and MDR (multi drug resistant) strains. The 16S rRNA sequence revealed that the MP56 was closely related to Bacillus subtilis with 99.93% homology. The optimal medium composition for production of antimicrobial substance in the B. subtilis MP56 were 1% mannitol, 1% oat meal, 0.01% $CaCl_2$. Antimicrobial activity of the culture broth against different pathogenic strains was assessed using the antimicrobial spectrum. The result suggests that Bacillus strain MP56 produces high quality antimicrobial substance that might be very useful to control varieties of pathogenic microbial growth.

• Korean Journal of Food Science and Technology
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• v.48 no.4
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• pp.361-365
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• 2016

This study was conducted to isolate and identify a microorganism that increases tricin-O-(threo-${\beta}$-guaiacylglyceryl) ether (TTGE) content in the hulls of rice (Oryza sativa L.). Bacteria from germinated rice were isolated by enrichment cultivation using yeast mold, luria bertani, potato dextrose and mannitol egg york polymyxin broths. The highest increase in TTGE content ($339.30{\mu}g/g$) was achieved by a microorganism isolated by PDA enrichment cultivation. On the basis of 16S RNA sequence homology and phylogenetic analysis, the isolated bacterium was identified to have 100% similarity with Burkholderia vietnamiensis. The isolated bacteria were short rods, negative for the Gram stain, and positive for the catalase test. The highest TTGE level was $435.86{\mu}g/g$ in 72-h fermented samples, representing a 2.5x increase compared with the control ($175.65{\mu}g/g$). In conclusion, the bacterium isolated from germinated rice extract was Burkholderia vietnamiensis, and the optimum fermentation period to maximize TTGE levels was 72 h. These findings might help in developing functional materials using rice hulls, a waste product of rice milling.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.758-766
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• 2015

Dextran is a generic term for a bacterial exopolysaccharide synthesized from sucrose and composed of chains of D-glucose units connected by ${\alpha}$-1,6-linkages by using dextransucrases. Dextran could be used as vicosifying, stabilizing, emulsifying, gelling, bulking, dietary fiber, prebiotics, and water holding agents. We isolated new strain capable of producing dextran from Korean traditional kimchi and identified as Leuconostoc sp. strain JYY4. Batch fermentation was conducted in bioreactor with a working volume of 3 L. The media was MMY and 15% (w/v) sucrose. Mineral medium consisted of $3.0g\;KH_2PO_4$, $0.01g\;FeSO_4$, $H_2O$, $0.01g\;MnSO_4$, $4H_2O$, $0.2g\;MgSO_4\;7H_2O$, 0.01 g NaCl, $0.05g\;CaCl_2$ per 1 liter deionized water. The pH of media was initially adjusted to 6.0. The inoculation rate was 1.0% (v/v) of the working volume. Temperature was maintained at $28^{\circ}C$. The agitation rate was 100 rpm. The production pattern of dextran was associated with the cell growth. After 24 hr dextran reached its highest concentration of 59.4 g/L. The sucrose was consumed completely after 40 hr. Growth reached stationery phase when sucrose became limiting, regardless of the presence of fructose or mannitol. When the specific growth rate was 0.54 hr-1, utilization averaged 5.8 g/L-hr. The yield and productivity of dextran were 80% and 2.0 g/L-hr, respectively. Dextrans produced by were separated to two different size by an alcohol fraction method. The size of high molecular weight dextran (45% alcohol, v/v), less soluble dextran, was between MW 500,000 and 2,000,000. Soluble dextran (55% alcohol, v/v) was between 70,000 and 150,000. The molecular weight average of total dextran (70% alcohol, v/v) was between 150,000 to 500,000. The enzymatic hydrolyzates of total dextran of ATCC 13146 showed branched dextrans by Penicillium dextranase contained of glucose, isomaltose, isomaltotriose, and isomaltooligosaccharides greater than DP4 (degree of polymerization) that had branch points. Compounds greater than DP4 were branched isomaltooligosaacharides. Hydrolysates by the Lipomyces dextranase produced the same composition of oligosaccharides as those by Penicillin dextranase.