• Asian-Australasian Journal of Animal Sciences
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• 제26권9호
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• pp.1304-1312
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• 2013

The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.494-500
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• 2010

Bacterial blight, an important and potentially destructive bacterial disease in rice, is caused by Xanthomonas oryzae. Recently, this organism has developed resistance to available antibiotics, prompting scientists to find a suitable alternative. This study focused on secondary metabolites of Phomopsis longicolla to target X. oryzae. Five bioactive compounds were isolated by activity-guided fractionation from ethyl acetate extracts of mycelia and were identified by LC/MS and NMR spectroscopy as dicerandrol A, dicerandrol B, dicerandrol C, deacetylphomoxanthone B, and fusaristatin A. This is the first time fusaristatin A has been isolated from Phomopsis sp. Deacetylphomoxanthone B showed a higher antibacterial effect against X. oryzae KACC 10331 than the positive control (2,4-diacetyphloroglucinol). Dicerandrol A also showed high antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and yeast (Candida albicans). In addition, high production yields of these compounds were obtained at the stationary and death phases.

• 한국수산과학회지
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• 제50권4호
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• pp.352-358
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• 2017

The object of this study is to assess physicochemical and microbiological hazards involved during the processing of shellfish products such as oysters, clam, and mussels. Samples including raw materials, intermediates, and final products in the processing process were collected from seven simple-processed shellfish facilities. In the samples obtained from the facilities, viable cell count and coliform group were detected less than that of the Korean Government guidelines. In addition, the high-risk bacterial pathogens such as Escherichia coli O157:H7, Salmonella sp., and Listeria monocytogenes were not identified in raw materials and final products. However, the low-risk pathogens, Staphylococcus aureus and Vibrio parahaemolyticus, were detected in some final products. The level of heavy metal content in the final products tested in this study meets the recommendations by the Korean Government standard guidelines. No foreign materials in the final products were also observed. Considering these results, it was concluded that no significant food hazards exists in the processing process of simple-processed shellfish products. However, it is essential to improve the food safety control in the shellfish processing facilities since S. aureus, a personal sanitary indicative bacterium, was continuously detected over seven simple-processed shellfish facilities.

• Natural Product Sciences
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• 제23권3호
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• pp.151-156
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• 2017

A phytochemical study of Alphonsea cylindrica King (unreported) has led to the isolation of six alkaloids. The compounds were identified as kinabaline (1; azafluorenone alkaloid), muniranine (2), O-methylmoschatoline (3; oxoaporphine alkaloid), lysicamine (4), atherospermidine (5) and N-methylouregidione (6; 4, 5-dioxoaporphine alkaloid). The structures of the isolated compounds were determined based on the spectroscopic techniques and by comparison with data reported in the literature. Alkaloid 2 was isolated as a new derivative of azafluorenone while alkaloids 1, 3 - 6 were isolated for the first time from Alphonsea species. In addition, alkaloid 3 and 4 showed inhibition zone against Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus in disc diffusion test. The minimum inhibition concentration (MIC) values of lysicamine (4) against S. aureus, B. cereus and P. aeruginosa were found to be smaller than O-methylmoschatoline (3). Therefore, the reported antibacterial activity showed the potential of this plant as natural antibacterial agent and supported the documented traditional use of Alphonsea sp. in the treatment of diarrhea and fever.

• 대한약침학회지
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• 제20권1호
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• pp.18-22
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• 2017

Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at $55-60^{\circ}C$. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.

• 한국수산과학회지
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• 제51권5호
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• pp.518-523
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• 2018

This study analyzed the food safety in processing process of simple-processed fishery products. A total of 88 samples analyzed for the presence of pathogenic bacteria and physicochemical hazards. No major foodborne pathogenic bacteria, such as Salmonella sp., Listeria monocytogenes and Escherichia coli O157:H7, were detected in any of the samples. However, Bacillus cereus (12 samples, 13.6%) and Staphylococcus aureus (15 samples, 17.0%) were frequently detected in both the intermediate processing stages and the final products, although cell populations were not high. Very small amounts of heavy metals and histamine were detected in some samples, in quantities that did not exceed the safe guidelines according to Korean Government regulations. Similarly, no other physical hazards such as foreign material were observed in any of the samples. We concluded that there are no significant pathogenic bacteria or physicochemical food hazards in simply processed fish products from Korea. The present study strongly suggests that increased food sanitation measures should be implemented to decrease the prevalence of S. aureus in simple-processed fishery products.

• 한국식품저장유통학회지
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• 제8권4호
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• pp.475-480
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• 2001

대나무의 추출물을 3$^{\circ}$Brix로 조정하였을 때 추출수율은 줄기가 1.0~1.5%였고, 잎은 3.1~3.2%로 잎의 추출수율이 줄기에 비해 높았다. 전자공여작용은 대조구인 죽력이 86%, BHT 93%, BHA 95%였고 줄기 추출물에서는 맹종죽 62%, 솜대 55%, 왕대 52%로 비교적 높은 활성을 나타내었으나, 잎 추출물에서는 미약하거나 나타나지 않았다. 아질산염소거능은 잎 추출물이 줄기 추출물에 비해 높게 나타내었는데, 맹종죽 63%, 왕대 57%, 솜대 55%의 순이었고, 줄기 추출물은 솜대와 왕대가 모두 10%를 나타내었으나, 맹종죽에서는 그 기능이 나타나지 않았다. 추출물의 항균환성은 주요 식중독균 중 그램 양성균 3종과 음성균 4종으로 시험하였는데, 전 죽종의 줄기 추출물은 각 균주에 대해 항균력을 보였으나, 잎 추출물은 줄기 추출물에 비해 약한 항균성을 보이거나 균주에 따라서는 전혀 항균활성을 나타내지 않았다. 균주중 Stapfylococcus aureus와 Vibrio parahaemolyticus에 대하여 모든 추출물이 비교적 높은 항균활성을 보였으며, 솜대줄기와 맹종죽잎의 추출물의 경우 이들 균주에 대해 100${\mu}\ell$/disc 이상의 농도에서 항균력이 인정되었다.

• Tuberculosis and Respiratory Diseases
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• 제42권5호
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• pp.777-780
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• 1995

살모넬라의 위장관 감염은 잘알려져 있으나 국소감염은 흔하지 않다. 저자들은 폐암으로 3차례의 항암제 치료을 받던 환자의 총상부위에서 농양이 발생되어 배양결과 salmonella group D가 동정된 1예를 경험하여 문헌과 함께 보고하는 바이다.

• Journal of Dairy Science and Biotechnology
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• 제29권2호
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• pp.81-85
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• 2011

Recently, antimicrobial resistance of microorganisms has been a major concern of its relation to food safety and national health, therefore, customer's needs to organic animal food is still increasing. In this study, we reviewed the usage of antimicrobials in animal farms and antimicrobial resistance of microorganisms isolated from organic dairy farm environments. The isolates from dairy farms were Acinetobacter sp., A. lwoffi, A. johnsonii, A. towneri, Aerococcus viridans, Aeromonas media, A. veronii, Bacillus pseudofirmus, B. pumilus, B. licheniformis, Corynebacterium glutamicum, Escherichia coli, Enterococcus faecium, Lysinibacillus fusiformis, Paenibacillus illinoisensis, Staphylococcus epidermidis, S. hominis, Streptococcus equinus, S. lutetiensis, and Saccharomyces cerevisiae. Indicator microorganisms isolated from organic dairy farms were tested for susceptibility to 20 types of antimicrobials. E. coli (ATCC 25922) isolated from dairy farm fence showed resistance to 8 types of antimicrobials, such as oxacillin, penicillin, vancomycin, etc., and E. faecium isolated from feces showed resistance to 9 types of antimicrobials, such as cephalothin, oxacillin, streptomycin, etc., respectively. However, these results showed less antimicrobial resistance compare with customary dairy farm.

• Fisheries and Aquatic Sciences
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• 제22권6호
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• pp.13.1-13.9
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• 2019

Background: Marine invertebrates are well known as pivotal bioresources with bioactive substances such as anti-inflammatory sterols, antitumor terpenes, and antimicrobial peptides. However, there are few scientific reports on chemical compositions and bioactivities of marine invertebrates from the East Sea of South Korea. Methods: In this study, chemical compositions and biological activities were evaluated on both 70% EtOH and hot water extracts of 5 species of marine invertebrates (Crossaster papposus japonicus, Actinostola carlgreni, Stomphia coccinea, Actinostola sp., and Heliometra glacialis) collected from the East Sea of South Korea. The antioxidant activities were measured by ABTS radical scavenging assay. The cytotoxicity and anti-inflammatory activity were evaluated using MTT and Griess reagents. Moreover, the antibacterial effect was evaluated using paper disc assay and minimum inhibitory concentration (MIC) assay. Results: In the results of antioxidant activities, 70% EtOH extract of A. carlgreni showed the highest activity ($IC_{50}\;0.19{\pm}0.03mg/ml$) compared to other extracts. Moreover, 70% EtOH extract of A. carlgreni could significantly suppress the nitric oxide (NO) production in lipopolysaccharide-induced RAW 264.7. All extracts treated under $400{\mu}g/ml$ have no cytotoxic effects on RAW 264.7 macrophages. In the antibacterial test, both 70% EtOH extracts of C. papposus japonicus and H. glacialis showed a significant antibacterial effect on Staphylococcus aureus. The MIC values were evaluated at 256 and $512{\mu}g/ml$, respectively. Conclusions: These results suggested the bioactive potentials of marine invertebrates from the East Sea of South Korea in pharmaceutical and nutraceutical applications.