• Journal of Mushroom
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• v.22 no.3
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• pp.122-127
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• 2024

This study was conducted to evaluate the market potential of 'Hwanggeumsantari', a new oyster mushroom variety developed in Gyeonggi Province in 2019, and to derive effective market entry strategies. To objectively assess the marketability of 'Hwanggeumsantari' from various perspectives, a panel of 50 consumers was formed, and surveys and interviews were conducted. Additionally, two Focus Group Interviews were held with distributors in the agri-food sector. The results showed that potential consumers were positive about the color and texture of 'Hwanggeumsantari', but expressed relatively less satisfaction with its shelf life and aroma. Distributors, through tow Focus Group Interviews, evaluated that the product had sufficient market competitiveness, but called for efforts to improve cultivation techniques and enhance price competitiveness. Based on the results of market evaluations by consumers and distributors, a SWOT analysis was conducted. The main strengths identified were its outstanding color and texture, while the main weakness was its freshness issue. Meanwhile, the growing demand for healthy foods and various online sales channels could provide market entry opportunities for 'Hwanggeumsantari', but high sensitivity to price in the case of premium pricing could pose a threat. Consequently, a market entry strategy for 'Hwanggeumsantari' was proposed using a 4P mix approach based on the SWOT analysis results. The product strategy emphasized premium positioning, small packaging, and the development of packaging technology to maintain freshness. The price strategy proposed premium pricing and the operation of incentive programs. The distribution strategy suggested channel diversification, direct stores, or direct sales, while the promotion strategy emphasized storytelling and collaboration with influencers.

• Journal of the Korean GEO-environmental Society
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• v.18 no.10
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• pp.15-22
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• 2017

The soil improvement method so far has been developed with an emphasis on enhancing the strength of the ground. A soil improvement method using a excellent cementitious stabilizer in economical efficiency and handling property is mainly used. The soil improvement method using cementitious stabilizer is effective but environmental and human harmful substances are detected and environmental problems such as carbon dioxide emission and groundwater pollution are pointed out. Therefore, as part of an alternative method capable of solving such problems, researches on the soil improvement method incorporating biological technology are being actively carried out. This study was conducted to investigate the characteristics of strength change when mixed with environmentally friendly soil binder and microorganism in clay, and it was analyzed by uniaxial compression test, direct shear test, SEM, XRD. As a results of the test, we confirmed the cementation caused by microbially induced calcite precipitation and the strength increase enhancement by it.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.430-435
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• 2010

This study was performed to investigate the antimicrobial effects of Ampelopsis brevipedunculata ethanol-extract on food spoilage or foodborne disease microorganism. The antimicrobial activity of Ampelopsis brevipedunculata extract was determined by a paper disc method. The extract exhibited growth inhibiting activities in a concentration dependent manner on 7 species of microorganisms. The extract of Ampelopsis brevipedunculata showed the highest antimicrobial activity against Escherichia coli O157:H7. The growth inhibitory effects of the extract at the concentration of 250, 500, 1,000, 2,000 mg/L on food poisoning microorganism were determined against Salmonella typhimurium, Yersinia enterocolitica, Escherichia coli O157:H7 and Staphylococcus aureus. The growth of microorganisms was not affected by the extract at the concentration up to 250 mg/L, but was significantly (p<0.05) inhibited by the extract at the concentration higher than 500 mg/L. The results in the present study demonstrate antimicrobial effects of Ampelopsis brevipedunculata ethanol-extract against foodborne pathogens, suggesting that Ampelopsis brevipedunculata could be an effective natural antibacterial agent in food.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.29-34
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• 2005

W/O/W (water-in-oil-in-water) type multiple emulsion was applied to improve the storage stability of an antagonistic microorganism, Burkholderia gladioli. Encapsulation of microorganism into a W/O/W emulsion was conducted by using a two-step emulsification method. W/O/W emulsion was prepared by the incorporation of B. gladioli into rapeseed oil and the addition of polyglycerin polyriconolate (PGPR) and castor oil polyoxyethylene (COG 25) as the primary and secondary emulsifier, respectively. Microcrystalline cellulose was used as an emulsion stabilizer. To evaluate the usefulness of W/O/W emulsion formulation as a microbial pesticide for controlling the bacterial wilt pathogen (Ralstonia solanacearum), the storage stability and antagonistic activity of emulsion formulation were tested in vitro. The storage stability test revealed that the viability of formulated cells in emulsion was higher than that of unformulated cells in culture broth. At $4^{\circ}C$, the viabilities of formulated cells and unformulated cells at the end of 20 weeks decreased to about 2 and 5 log cycles, respectively. At $37^{\circ}C$, the viability of formulated cells decreased to only 2 log cycles at the end of storage. On the other hand, the viable cells in culture broth were not detected after 13 weeks. In activity test, formulated cells in emulsion were more effective in inhibiting the growth of pathogen than unformulated cells in culture broth. Unformulated cells completely lost their antagonistic activity during storage under similar conditions. The W/O/W multiple emulsion formulation was shown to be useful as the novel liquid formulation for biological control.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.452-454
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• 2002

A biosurfactant-producing microorganism, .Pseudomouos sp. EL-G527 was isolated from activated sludge by enrichment culture when grown on mineral salt medium containing n-hexadecane as a carbon source. The biosurfactant from .Pseudomonar sp. EL-G527 exhibited lesser toxicity to bacterial population than synthetic surfactants and in the biodegradation test, biosurfactant was rapidly degraded and lost its activity as surface active material after 1 day incubation. In this study, the biosurfactant from Pseudomonas sp. EL-G527 was effective surface-active compound, more biodegradable and less toxic to microbial ecosystem than various synthetic surfactants.

• YAKHAK HOEJI
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• v.26 no.3
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• pp.169-174
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• 1982

Several strains of bacteria having resistance to macrolide antibiotics were isolated. EMR-1, one of them, exhibited the induced resistance to macrolide antibiotics and this microorganism was identified as a bacterium belong to Bacillus species. The subinhibitory concentration of erythromycin or oleandomycin induced strong resistance to both erythromycin and oleandomycin themselves and to other macrolide antibiotics such as leucomycin, spiramycin and josamycin. The effective concentration of inducer, erythromycin was $0.0016-0.2\mu$g/ml. The inactivating enzyme of these antibiotics was not produced by EMR-1.

• KSBB Journal
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• v.13 no.5
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• pp.469-476
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• 1998

Among 31 water-born microbial strains isolated from various sites in Korea, strain DJ-4 was selected as a test organism for toxicity measurements in that its growth was completely inhibited by the presence of 668.4 mg/L of chloroform and 297.5 mg/L of toluene in the liquid LB medium whereas others did not. It was observed that lag periods and specific growth rates of DJ-4 batch vial cultures were prolonged and decreased, respectively, by phenol, benzene, toluene, ethylbenzene, p-xylene, perchloroethylene, trichloroethylene, and chloroform at the concentrations between 3.6 and 417.8 mg/L. There changes were found to be linear with respect to the concentrations of the toxic compounds. From the first-order regression equations, 50% effective concentrations (EC50${\mu}$ for concentrations of toxic compounds causing 50% decrease of specific growth rates and EC50lag for 50% increase of length of lag periods) were calculated for each compounds. By comparing DJ-4 EC50${\mu}$ values with Daphnia LC50's from a literature for benzene, ethylbenzene, toluene, and trichloroethlyene, it was concluded that microbial specific growth could be a new, fast, and reliable parameter for toxicity tests.

• Journal of Korean society of Dental Hygiene
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• v.14 no.1
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• pp.117-122
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• 2014

Objectives : The purpose of the study is to investigate the activities of Nelumbo nucifera leaf extracts on Streptococcus mutans, Streptococcus mitis, Streptococcus sobrinus, Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola. Methods : The inhibitory effect of lotus leaf extracts on the growth of oral bacteria was assessed in experiments with extracts from freshly harvested and pulverized lotus leaves and bacterial cultures of dental caries. Results : The results showed that N. nucifera extracts possess antimicrobial activity on all bacterial strains. The minimal inhibitory concentration (MIC) values varied from 4 mg/ml to 10 mg/ml against antimicrobial activity. The relative growth ratio (RGR) against of N. nucifera extracts were determined as 50% in concentration of 4.0 mg/ml. The extract of N. nucifera was effective in reducing on the glucosyltransferase (GTase) activity of six strains in vitro. Conclusions : Methanol extracts of lotus leaves showed antimicrobial effects on three bacterial species causing dental caries and three bacterial species causing periodontitis, as well as inhibitory effects on GTase activity.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.121-127
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• 2004

It is necessary to supply external carbon source for enhancement of biological nitrogen removal from domestic wastewater with low influent C/N ratio. Sulfide was chosen as a cost effective electron donor and reaction stoichiometry for autotrophic denitrification was investigated by conducting bench-scale experiments in this study. Higher sulfur to nitrogen (S/N) ratio than the calculated value from theoretical reaction stoichiometry was required when the anoxic reactor was operated at open condition because dissolved oxygen introduced by surface aeration reacted with sulfide with ease. In addition, higher sulfate production and lower yield of microorganism could be observed under the same condition. It was possible to obtain reliable reaction stoichiometry for autotrophic denitrification by establishing pure anoxic condition. Linear relationship between bacterial growth and consumption of nitrate, sulfide, alkalinity, and sulfate production enabled to derive a relatively correct reaction stoichiometry for autotrophic denitrification when sulfide was used as an electron donor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.652-659
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• 2021

Microorganism-derived compounds, such as peptidoglycan, lipoteichoic acid, and β-glucan were supplemented in the scuticociliate Miamiensis avidus (M. avidus) vaccine to verify the specify component contribution to the adjuvant effect. Vaccine was formulated with the inactivated M. avidus antigen (YS2, 4.44×10⁵ cells/fish) in combination with either peptidoglycan (10 ㎍ and 100 ㎍/fish), lipoteichoic acid (5 ㎍ and 50 ㎍/fish), or β-glucan (10 ㎍ and 100 ㎍/fish). Olive flounder injected with peptidoglycan supplemented vaccine (10 ㎍ and 100 ㎍/fish) exhibited significant protection, and the relative percent survival (RPS) was 55% and 65% at 4 weeks post vaccination (wpv), respectively, at the corresponding doses. The vaccine groups with added lipoteichoic acid (5 ㎍ and 50 ㎍/fish) exhibited RPS of 40% and 5%, respectively. Additionally, the group with added β-glucan (100 ㎍/fish) exhibited RPS of 35%, but no effect was observed in the group with added 10 ㎍/fish β-glucan. At 8 wpv, olive flounder injected with peptidoglycan and lipoteichoic acid supplemented vaccines exhibited protection with RPS range of 11/11% and 5/21%, respectively, at the respective doses. M. avidus vaccine containing 10 ㎍ and 100 ㎍/fish of β-glucan exhibited the RPS of 32% and 37%, respectively. Conclusively, peptidoglycan contributed in high protection of the M. avidus vaccine, and thus, it can be used as an effective adjuvant in the M. avidus vaccine.