• Journal of Environmental Science International
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• v.12 no.8
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• pp.847-852
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• 2003

It was examined carefully that the bacterial die-off between Chlorella vulgaris and E. coli. W3110 was tested through adding TOC (total organic carbon) with the lab-scaled continuous river water flow system (CRWFS). Artificial synthetic wastewater was applied at two levels of organic carbon concentration; 1,335 mg/l in treatment type 1 and 267 mg/l in type 2. In both types, the population densities of Chlorella vulgaris were similar in a maximum 8.25 ${\times}$ 10$\^$6/ cells/ml (type 1) and 6.925 ${\times}$ 10$\^$6/ cells/ml (type 2). The maximum densities of E. coli. W3110 were 2.0 ${\times}$ 10$\^$8/ colony forming unit (CFU)/ml in type 1 and 3.9 ${\times}$ 10$\^$8/ CFU/ml in type 2. The densities increased for 11 days in type 1 and 4 days in type 2, then decreased rapidly till the 35th day, then slightly increased again. This trend was prominent in type 2. It implied that a wider range of nutrients was required in the growth of heterotrophic bacteria in type 2 than in type 1. We could not expect successful bacterial die-off if the wastewater retention time was not furnished sufficiently.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.5
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• pp.383-388
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• 2004

The conversion of a cellulose-producing cell ($Cel^+$) from Gluconacetobacter hansenii PJK (KCTC 10505 BP) to a non-cellulose-producing cell ($Cel^-$) was investigated by measuring the colony forming unit (CFU). This was achieved in a shaking flask with three slanted baffles, which exerted a strong shear stress. The addition of organic acid, such as glutamic acid and acetic acid, induced the conversion of microbial cells from a wild type to $Cel^-$ mutants in a flask culture. The supplementation of $1\%$ ethanol to the medium containing an organic acid depressed the con-version of the microbial cells to $Cel^-$ mutants in a conventional flask without slanted baffles. The addition of ethanol to the medium containing an organic acid; however, accelerated the conversion of microbial cells in the flask with slanted baffles. The $Cel^+$ cells from the agitated culture were not easily converted into $Cel^-$ mutants on the additions of organic acid and ethanol to a flask without Slanted baffles, but some portion of the $Cel^+$ cells were converted to $Cel^-$ mutants in a flask with slanted baffles. The conversion ratio of $Cel^+$ cells to $Cel^-$ mutants was strongly re-lated to the production of bacterial cellulose independently from the cell growth.

• The Korean Journal of Community Living Science
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• v.18 no.3
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• pp.399-406
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• 2007

Soybean seeds were fermented by Bacillus subtilis and/or Lactobacillus bulgaricus to improve solubility, viscosity, water holding capacity and oil holding capacity of soybean proteins in Chongkukjang. The maximum colony forming unit and protease activity of B. subtilis or L bulgaricus were observed after 60 hours of fermentation, and those of the mixed fermentation by two microorganisms were steadily increased during the fermentation periods. Solubilities of soybean proteins by B. subtilis or L bulgaricus were steadily increased before the values were considerably increased to 60 hours of fermentation, whereas water holding capacities of the proteins were decreased by B. subtilis or L. bulgaricus and those of the mixed fermentation were decreased progressively. Viscosities of soybean proteins by B. subtilis and/or L. bulgaricus were decreased progressively during the fermentation. Viscosities of soybean proteins by B. subtilis and/or L. bulgaricus were decreased progressively during the fermentation. Oil holding capacities of soybeans by B. subtilis or L. bulgaricus were maximum at 20 or 80 hours of fermentation and those of the mixed fermentation were decreased after 10 hours of the fermentation.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.694-697
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• 1993

Soymilk was cultured by various human large intestinal bacteria and lactic acid bacteria; Bifidobacterium longum, Lactobacillus acidophilus, Baeteroides fragilis, Eubacterium limosum, Clostridium perfringens and Escherichia coli. Among them, only B. longum utilized raffinose and stachyose actively which are major oligosaccharides present in soymilk by producing active ${\alpha}-galactosidase$ and produced greatest acid. Number of colony forming unit of B. longum reached $1.5{\times}10^{8}$ after 16 hr culture in soymilk. Also Bifidobacterium longum produced the highest level of ${\alpha}-galactosidase,\;{\beta}-galactosidase\;and\;{\alpha}-galactosidase$, in soymilk during culture.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.63-71
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• 1986

The antifungal activities of amphotericin B, 5-fluorocytosine, and ketoconazole in combination of amphotericin B/ketoconazole and 5-fluorocytosine/ketoconazole were determined against 42 strains of Candida spp. isolated from oral cavity. Among 42 strains of Candida species, 36 strains of Candida albicans, 2 strains of Candida parapsilosis and Candida tropicalis 1 strain of Candida krusei and Candida stellatoidea were identified. The minimum inhibitory concentrations(MICs) of amphotericin B, 5-fluorocytosine and ketoconazole for these strains were ranged from 0.05-1.56 mcg/ml, 12.5->100.0 mcg/ml and 0.2-50.0 mcg/ml. In all of the experimental strains, amphotericin B had the greatest antifungal activity on a dilution basis. When a microtiter checkerboard technique was used 5-fluorocytosine acted synergistically with ketoconazole against all strains, whereas amphotericin B has a reduced effect. The killing curve experiments with on strain of Candida albicans WMC-85024 demonstrated that the combination of amphotericin B/ketoconazole and 5-fluorocytosine/ketoconazole produced a decrease in number of colony forming unit of >3 logs in 72 hours.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.1
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• pp.41-48
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• 1989

The significance of soil and/or rhisosphere populations of Erwinia carotovora sobsp. carotovora (Ecc) as a source of primary inoculum for tobacco hollow stalk disease has been demonstrated conclusively. The survival of Ecc in field soils fter overwintering was estimated by using the enrichment technique. The population number of pectolytic erwinia (PE) in field soils relatively decreased at the rate of 102-104 colony forming unit(CFU) per g of soil after overwintering. Higher level of PE population overwintered in the rhlzosphere foils of tobacco stubbles and detected more frequently in rhizosphere soils of weed plants than in those of bare fields. All of the tobacco stubbles collected from fields where tobacco had been grown the previous year contained Ecc. The more survived population number of PE at the 30cm depth of artifitiany infested soils than at the upper of those by introducing with diseased tobacco plant tissue after overwintering. Ecc overwintered effectively in rhizosphere soils of tobacco stubbles, overwintered weeds and tobacco debris in field soils.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.25-30
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• 2000

Bacterial wilt(Ralstonia solanacearum) is one of the major diseases of flue-cured tobacco (Nicotiana tabacum L.) in the world. This study was conducted to investigate degree of dominance, selection, and correlation between leaf shape and degree of bacterial wilt resistance in flue-cured tobacco. The degree of disease caused by bacterial wilt was evaluated in parents, F$_1$, F$_2$ and F$_3$ populations of two crosses, BY 4 x NC 95 and BY 4 x Coker 86, in the infected field. The leaf shape index was also measured in parents and F$_2$ population of BY 4 x NC 95. The incidence of bacterial wilt was observed in the middle of June and peaked in late July, when the highest value of pathogen density reached 1.0 x 10$^{6}$ colony forming unit per gram. It was concluded that the inheritance mode of risestance to bacterial wilt in the above two crosses of susceptible and resistant varieties was recessive and polygenic. The resistance to bacterial wilt was significantly correlated with leaf shape in F2 generation of BY 4 x NC 95. But certain plants having narrower leaves were also resistant to bacterial wilt. It is considered that the bacterial wilt resistant lines having narrower leaves could be selected. The selection for bacterial wilt resistance in the F$_2$ population might be effective.

• Food Science of Animal Resources
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• v.35 no.5
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• pp.611-614
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• 2015

This study was performed to apply a protein film containing a natural antimicrobial compound to meat packaging and determine quality change of meat during storage. Proteins obtained from the by-products of food processing have been utilized as biodegradable film sources. Porcine meat and bone meal (MBM) is obtained during meat processing, and proteins from the MBM can be extracted and used as a film base material. Previously, an antimicrobial MBM film containing coriander oil (CO) was prepared and its physical properties and antimicrobial activity were characterized. In this study, the antimicrobial MBM-CO film was applied to beef patties packaging, and the microbial population and the degree of lipid oxidation were determined during storage at 4℃ for 15 d. The population of inoculated E. coli O157:H7 in the samples wrapped with the MBM-CO film was 6.78 log colony forming unit (CFU)/g after 15 d of storage, whereas the control had 8.05 Log CFU/g, thus reducing the microbial population by 1.29 Log CFU/g. In addition, retardation of lipid oxidation in the patties was observed during storage for the samples packaged by the MBM-CO film, compared with the control samples. These results suggest that the MBM-CO film can be useful for enhancing the quality of beef patties during storage.

• YAKHAK HOEJI
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• v.44 no.4
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• pp.347-353
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• 2000

To examine influence of artificial digestive juice on the antitumor activity of Ganoderma lucidum-A(GL-A), protein-bound polysaccharide from Ganoderma lucidum, we compared the digested protein-bound polysaccharide with undigested one both on immunopotentiating activity and influence of digestive juices. Protein-bound polysaccharide GL-B was obtained by digesting the antitumor component GL-A with artificial digestive Juices in vitro. When GL-A was administered orally to sarcoma 180 tumor-bearing ICR mice, the life prolonging effect was exhibited in a dose dependent manner Not only GL-A but GL-B increased the production of colony forming unit (CFU) to 10- and 8-fold of that of the control, respectively. Both of the protein-bound polysaccharides also showed the secretion of nitric oxide in RAW 264.7 cell lines to 3.5-and 3.7-fold of that of the control, respectively: GL-A activated components of the alternative complement pathway, whereas GL-B did not. In humoral immunity GL-A increased the activity of alkaline phosphatase in differentiated B cells to 3 times and GL-B to 4 times of that of the control. These results showed that the artificial digestive juices had no influence on the antitumor activity of the protein-bound polysaccharide from Ganoderma lucidum and that its immunomodulating activity retained after treatment with artificial digestive juice. And this provides a basis of the protein-bound polysaccharide of Ganoderma lucidum as an peroral anticancer drug.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.119-124
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• 2013

The aim of this present study was to investigate the antifungal effect of tanshinones isolated from Salvia miltiorrhiza against Candida ablicans, a polymorphic fungus. For the work, tanshinone IIA (TSN), cryptotanshinone (CTS), and dihydrotanshinone I (DTS) were chosen. Initially, their antifungal effect was analyzed by in-vitro susceptibility test. Data from the susceptibility test showed that while all of these three compounds had antifungal activity, DTS was the most potent. At $100{\mu}g$ DTS/ml, there was about 80% CFU (colony forming unit) reduction as compared to DTS-untreated C. albicans yeast cells (P<0.05). Thus, DTS was selected to determine its antifungal activity in a murine model of disseminated candidiasis due to C. albicans. Results showed that DTS enhanced resistance of mice against disseminated candidiasis. During the entire period of 30-day observation, 60% of DTS-given mice groups survived whereas control animals all died within 14 days (P<0.05). Moreover, DTS inhibited the hyphal production, one of the virulence factors of this fungus, from the blastoconidial form of the fungus. Therefore, the tanshinone appears to have antifungal activity specific for C. albicans infection, which could possibly be mediated by the blockage of hyphal production.