• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.611-617
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• 2011

This study investigated the germination and reduction of microbial population in domestic (radish, Chinese cabbage, and vitamin) and imported (radish and red cabbage) sprout seeds by heat treatment (40, 50, 60, and 70$^{\circ}C$ for 15 min or 30 min). The germination ratio (define the ratio) was 45-97% at 24 h after treatment <60$^{\circ}C$ and was decreased at 70$^{\circ}C$. In domestic radish seed, total aerobic bacteria were decrease by approximately 1.71 log CFU/g after heat treatment at 70$^{\circ}C$ for 30 min and viable coliforms were decreased to under the detection limit at temperatures over 60$^{\circ}C$. Decrease of total aerobic bacteria and coliforms in domestic Chinese cabbage seed was 1.23-1.34 and 2.77 log CFU/g, respectively, after heat treatment over 60$^{\circ}C$. In domestic vitamin seed, total aerobic bacteria were decreased by about 0.3 log CFU/g at 70$^{\circ}C$ for 15 min. In imported radish seed, total aerobic bacteria were decreased 2.12-2.30 log CFU/g after heat treatment over 60$^{\circ}C$. Total aerobic bacteria in imported red cabbage seed were reduced by 0.66-0.84 log CFU/g after heat treatment over 40$^{\circ}C$ and coliforms were undetectable. In case of Bacillus cereus, there was no significant difference by heat treatment in any sample. Staphylococcus aureus and Salmonella sp. were not detected at the detection limit in any tested seeds at any temperature.

• Tuberculosis and Respiratory Diseases
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• v.55 no.1
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• pp.59-68
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• 2003

Background : In intubated patients, cultures of endotracheal aspirates (EA) are apt to contamination throughout the endotracheal tube. Therefore, the identification of etiologic agents via conventional EA cultures is not always reliable. In order to differentiate a pulmonary infection from a non-infectious disease, and to identify the true etiologic agent of acute pulmonary infection, blinded protected specimen brushing (PSB) was used, and its efficacy evaluated. Methods : In 51 intubated patients, with suspected pneumonia, blind PSB were performed, and the results compared with blood and EA cultures. A protected specimen brush was introduced through the endotracheal tube, and settled at the affected large bronchus. A specimen brush was introduced to the expected region using the blind method. The tip of the brush was introduced with an aseptic technique after vigorously mixed for 1 minute in $1cm^3$ of Ringer's lactate solution. The specimens were submitted for quantitative culture within 15 minutes, with a culture being regarded as positive if the colony forming units were above $10^3/ml$. Results : Of the 51 patients, 15 (29.4%) had community-acquired pneumonia (CAP), 27 (52.9%) hospital-acquired pneumonia (HAP) and 9 (17.6%) non-infectious diseases. The sensitivity and specificity of the quantitative PSB culture for the diagnosis of pneumonia were 52.4 and 88.9%, respectively. The sensitivity and specificity of EA were 78.6 and 77.8%, respectively. The blind PSB was superior to the EA for the identification of true etiologic agents. Of 53 episodes of 27 HAP patients, MRSA (Methicillin-resistant staphylococcus aureus) (41.5%) was the most common causative agent followed by Pseudomonas aeruginosa (15.1%), Klebsiella sp. (7.5%) and Acinetobacter sp. (7.5%). Conclusions : As a simple, non-invasive diagnostic modality, the blind PSB is a useful method for the differentiation of a pulmonary infection from non-infectious diseases and to identify the etiologic agents in intubated patients. A blind PSB can be performed without bronchoscopy, so is safer, more convenient and cost-effectiveness for patients where bronchoscopy can not be performed.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.134-140
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• 2012

Asian dust storms originating in the arid desert of China and Mongolia usually occur from late winter through spring, and more than one million tons of dust per year is transported to the Korean Peninsula by the prevalent westerly winds. We supposed that these dust particles could include bioaerosols and act as carriers of microorganisms. In order to clarify the dynamics of microorganisms moving with these particles, the concentration and composition of microorganisms associated with settled particles were compared between samples collected during Asian dust events and those under non-dust periods. From February to April 2008, settled dust particles were collected at one location in Ulsan using rainfall meter of 200 mm diameter. During this period, there was one Asian dust event in Ulsan. The bacterial concentrations were higher in samples collected during Asian dust event than those under non-dust period, whereas fungal concentrations were rather similar regardless of the Asian dust event. We analyzed 16S rRNA gene sequences of 45 bacterial isolates obtained from the settled particle samples. These isolates belonged to either genus Bacillus or genus Streptococcus and were tentatively identified as B. amyloliquefaciens, B. aryabhattai, B. atrophaeus, B. licheniformis, B. megaterium, B. methylotrophicus, B. pumilus, B. sonorensis, B. subtlis, B. vallismortis, S. epidermidis, and S. succinus. In cases of fungal isolates, genera such as Mucor, Alternaria, Cladosporium, and Aspergillus were tentatively identified from samples collected at both Asian dust and non-Asian dust periods. It appears that endospore-forming bacteria such as Bacillus sp. rather than fungal spores are more likely to be associated with Asian dust particles.

• Journal of Life Science
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• v.27 no.6
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• pp.646-651
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• 2017

This study was carried out to examine the antimicrobial activity of 70% ethanol and hot water extracts from different parts and essential oil in Pinus densiflora on skin pathogens such as Staphylococcus epiermidis, S. aureus, Propionibacterium acnes, Candida albicans, C. tropicalis, and Trichophyton rubrum. The antimicrobial activities of extracts and essential oil were tested by paper disc assay and minimum inhibitory concentration test. The ethanol extract of pine pollen showed antimicrobial activity against C. tropicalis and T. rubrum. Ethanol extract of pine needle and pine gnarl showed antimicrobial activity against S. aureus, C. tropicalis, and P. acnes. Essential oil from pine needle exhibited antimicrobial activity against C. albicans, C. tropicalis, and P. acnes. The minimum inhibitory concentration of ethanol extracts of pine needle and pine gnarl against P. acnes and C. tropicalis ranged from 0.002% to 0.0063%. The lowest minimum inhibitory concentration (0.025%) against C. albicans and C. tropicalis was obtained from essential oil. These results indicate that ethanol extracts of pine pollen, pine needle, pine gnarl, and essential oil of pine needle could be applicable to control the skin infection pathogens. Especially, ethanol extract of pine gnarl had a broad spectrum of antimicrobial activity and pine extracts and essential oil exhibited higher antimicrobial activity with Candida sp. and P acnes.

• Journal of Life Science
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• v.27 no.2
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• pp.202-210
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• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.35-41
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• 2006

Antibacterial activities of the trace elements in combination with the food additives were measured against 6 kinds of food-borne microorganisms such as Escherichia coli, Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Pseudomonas fluorescens. The difference of antibacterial activity was not shown among the kinds of food additives, such as dextrin, gelatin and collagen. Zn and Ge in combination with food additives had strong antibacterial effect. Especially, $1\%$ zinc acetate in combination with $1\%$ gelatin was more effective against P. fluorescens and S. aureus than against Bacillus sp., E. coli and V. parahaemolyticus. Minimum inhibitory concentration of zinc acetate in combination with $1\%$ gelatin appeared to be 0.5 mg/mL on S. aureus and P. fluorescens, and 1.0 mg/mL on E. coli, V. parahaemolyticus, B. cereus and B. subtilis. Minimum bactericidal concentration of zinc acetate in combination with $1\%$ gelatin appeared to be 0.5 mg/mL on P. fluorescens and 1.0 mg/mL on E. coli, V. parahaemolyticus, S. aureus, B. cereus and B. subtilis. The zinc acetate in combination with gelatin showed stronger inhibitory effect in acidic range below pH 6.0, and remained active even after heat treatment at $121^{\circ}C$ for 15 min. In comparison with control, the viable cell counts of fish pastes, which were coated with the solution containing both $1\%$ zinc acetate and $3\%$ gelatin, were decreased by more than 100-fold until the storage of 7 days at $10^{\circ}C$. The results indicate that the combined use of zinc acetate and some food additives could prolong the shelf life of fish pastes by 8 days or more at $10^{\circ}C$.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.382-390
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• 2009

This study was carried out to determine the effects of tomato powder (TP) as nitrite (NT) on pork patties. The following treatments were made: 0.01% NT (Tl), 0.01% NT and 1.0% TP (T2), 0.5% TP (T3), 1.0% TP (T4), and 0.01% NT and 1.0% TP (T5) were in basal formula (C). The following observations were made: T5 displayed lower gumminess and adhesiveness values than those of C and T1 (p<0.05) on Day 1 of storage; the hardness and surface hardness of T3 and T4 were relatively lower and the surface hardness and gumminess of T3 were relatively higher than the others (p<0.05) on Day 21 of storage; Y4 had significantly lower TBARS values than the others during storage; VBN values of the tested groups were significantly lower than the control samples on Day 7 and 21 of storage; T3 and T4 samples displayed lower pH values (p<0.05) than the control samples on Day 21 of storage; T3, T4 and T5 revealed lower CIE $L^*$ and W than those of C and T1 during storage; T2 had the highest CIE $a^*$ (p<0.05); T4 had significantly higher CIE $b^*$ and chroma values than those of others; T3 and T4 had significantly lower total plate counts than the others; T1 had significantly lower yeast and mold and Staphylococcus sp. counts than the other groups'; and T1 and T2 displayed significantly higher color acceptability than the others.