• Korean Journal of Microbiology
• /
• v.52 no.1
• /
• pp.84-97
• /
• 2016

Isolates from Korean fermented soybean paste were identified as Enterococcus faecium SBP12, Pediococcus halophilus SBP20, Lactobacillus fermentum SBP33, Leuconostoc mesenteroides SBP37, Pediococcus pentosaceus SBP41, Lactobacillus brevis SBP49, Lactobacillus acidophilus SBP55, and Enterococcus faecalis SBP58 according to conventional morphological and biochemical characteristics, carbohydrate fermentation profiling, and 16S rRNA sequence comparison. Strain SBP20, SBP33, SBP49, and SBP55 showed very resistance to simulated gastric and intestinal juices with final populations exceeding 6 log CFU/ml, whereas cells of SBP12 and SBP58 after exposure to low pH were dramatically decreased within 2 h. Among 4 strains having good tolerance to gastrointestinal conditions, the high adhesive ability to HT-29 cells, antibiotic resistance, and antimicrobial activity against food-borne pathogens Bacillus cereus ATCC 11778 and Staphylococcus aureus ATCC 6538 were observed with SBP49 and SBP55, therefore, these two strains were confirmed as putative probiotic candidates. There was no significant difference between the sourdoughs fermented with SBP49 and SBP55 with respect to the values of pH, total titratable acidity, and viable cell count. During sourdough fermentation, SBP49 strain produced significantly greater amounts of lactic acid than SBP55 strain, which secreted large quantities of hydrogen peroxide. SBP49 and SBP55 strains producing the antimicrobial substances such as lactic acid, hydrogen peroxide, and bacteriocin effectively inhibited B. cereus and S. aureus inoculated in the sourdough.

• Applied Microscopy
• /
• v.39 no.3
• /
• pp.237-243
• /
• 2009

Chinese minnow, Rhynchocypris oxycephalus is a teleost belonging to Leuciscinae, Cyprinidae. The oogenesis and ultrastructure of egg envelope in Chinese minnow were investigated by light and electron microscopes. The ovary was of white yellowish and ellipsoidal shape with the major axis 30 mm and the minor axis 7mm. Cytoplasm of oogonia was basophilic and many nucleoli were located at inside of nuclear membrane. In primary oocytes, yolk vesicles were distributed only in the marginal area and egg envelope was not formed on the outside of an egg. In secondary oocytes, the egg envelope was formed and yolk vesicles in the cytoplasm were increased than the earlier stage. The basophilic substance of cytoplasm was changed to acidic. In case of matured egg, thickness of egg envelope and size of egg were increased. The yolk vesicles were changed to yolk mass in accordance with development. The outer surface of egg envelope was covered by microvilli-structures, and had a micropyle on the area of animal pole. Egg envelope consisted with 2 layers, an adhesive outer layer with microvilli-structures and fibrillar inner layer. In conclusion, the oogenesis of Chinese minnow was characterized by the increase in cell size, the formation and accumulation of yolk, and the decrease of basophilic substance in the cytoplasm. The oogenesis of Chinese minnow seems to share common patterns in Cyprinidae, but these ultrastructural unique characters of egg envelope can be utilized in taxonomy of teleost.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.6
• /
• pp.3736-3741
• /
• 2015

Crash impact test is conducted to verify the crashworthiness of fuel tank. Success of the crash impact test means the improvement of survivability of crews by preventing post-crash fire. But, there is a big risk of failure due to huge external load in the crash impact test. The failure of crash impact test can result in serious delay of a entire rotorcraft development because of the design complement and re-production of the test specimens requiring a long-term preparation. Thus, the numerical simulations of the crash impact test has been required at the early design stage to minimize the possibility of trial-and-error in the real test. Present study conducts on the numerical simulation of phase I crash impact test using SPH supported by crash simulation software, LS-DYNA. Test condition of MIL-DTL-27422 is reflected on analysis and material data is acquired by specimen test of fuel cell material. As a result, the crash load on the skin material, overlap area and metal fitting is estimated to confirm the possibility of acquisition of the design load for the determination of the overlap area and adhesive strength.

• Korean Journal of Microbiology
• /
• v.40 no.4
• /
• pp.286-294
• /
• 2004

Between 1997 and 1998 in Korea, 56 isolates of Escherichia coli were obtained from pig suffering diarrhea. Among those, 38 isolates that showed the hemolytic activity, antimicrobial resistance, and toxin production were studied. Among 38 isolates, thirty-six isolates $(94.7\%)$ were resistant to tetracycline, 27 isolates $(71.0\%)$ were resistant to ampicillin, 26 isolates $(68.4\%)$ were resistant to chloramphenicol, and 21 isolates $(55.2\%)$ were resistant to trimethoprim, while none was resistant to aztreonam, amikacin, and norfloxacin. Among these iso­lates, 21 isolates $(55.3\%)$ were multiple drug resistant to at least four different class antimicrobial agents. Extended spectrum $\beta-lactamase$ producing isolates were not detected in the double disk synergy test. In these hemolytic Escherichia coli, heat-stable enterotoxin $(89.5\%)$ was the most prevalent toxin, followed by vero­toxins $(47.4\%),$ and then heat-labile enterotoxin $(31.6\%).$ Except 8 isolates $(21.0\%)$ which produced ST only, 12 isolates $(31.6\%)$ produced ST and LT, 13 isolates $(34.2\%)$ produced ST, VT, and VTe, and 5 isolates $(13.2\%)$ produced VT and VTe. However, none produced all 4 types of toxin, simultaneously. The predominant serotype could not be determined by the agglutination method. Sixteen isolates $(42.1\%)$ were strongly adhered to T-24 bladder cell and 17 isolates $(44.7\%)$ were to Caco-2 intestinal cell. Especially, 11 strains $(28.9\%)$ were evaluated as strongly adhesive to both T-24 cells and Caco-2 cells. Genes for toxin and the antimicrobial resistance were transferred to clinical isolates of Escherichia coli from human urine by the filter mating method. Results suggest the possibility that antimicrobial resistance and toxin can be transferred from animals to humans by direct con­tact of resistant bacteria as well as gene transfer, although there was no correlation between toxin production, adherent activity, and antimicrobial resistance among hemolytic E. coli isolated from pig suffering diarrhea.

• Tuberculosis and Respiratory Diseases
• /
• v.71 no.3
• /
• pp.195-201
• /
• 2011

Background: Osteopontin (Opn) is recognized as an important adhesive bone matrix protein and a key cytokine involved in immune cell recruitment and tissue repair and remolding. However, serum levels of osteopontin have not been evaluated in patients with chronic obstructive pulmonary disease (COPD). Thus, the aim of this study was to evaluate and compare the serum levels of osteopontin in patients experiencing COPD exacerbations and in patients with stable COPD. Methods: Serum samples were obtained from 22 healthy control subjects, 18 stable COPD patients, and 15 COPD with exacerbation patients. Serum concentrations of osteopontin were measured by the ELISA method. Results: Serum levels of osteopontin were higher in patients with acute exacerbation than with stable COPD and in healthy control subjects ($62.4{\pm}51.9ng/mL$, $36.9{\pm}11.1ng/mL$, $30{\pm}11ng/mL$, test for trend p=0.003). In the patients with COPD exacerbation, the osteopontin levels when the patient was discharged from the hospital tended to decrease compared to those at admission ($45{\pm}52.1ng/mL$, $62.4{\pm}51.9ng/mL$, p=0.160). Osteopontin levels significantly increased according to patient factors, including never-smoker, ex-smoker and current smoker ($23{\pm}5.7ng/mL$, $35.5{\pm}17.6ng/mL$, $58.6{\pm}47.8ng/mL$, test for trend p=0.006). Also, osteopontin levels showed a significantly negative correlation with forced expiratory volume in one second ($FEV_1$%) predicted in healthy controls and stable COPD patients (r=-0.389; p=0.013). C-reactive protein (CRP) was positively correlated with osteopontin levels in patients with COPD exacerbation (r=0.775; p=0.002). Conclusion: The serum levels of osteopontin increased in patients with COPD exacerbation and tended to decrease after clinical improvement. These results suggest the possible role of osteopontin as a biomarker of acute exacerbation of COPD.

• Korean Journal of Ichthyology
• /
• v.35 no.4
• /
• pp.263-269
• /
• 2023

This study aims to contribute to the research on resource recovery for the rapidly declining population of Liparis tanakae by observing the larval development process and the morphology of juveniles based on their growth. Natural spawning eggs collected in Yeosu were used for observing the process of egg development and larval morphology. The water temperature during the rearing process was maintained at 12.3~13.5℃ (average 12.7℃). The fertilized eggs had an egg diameter ranging from 1.57 to 1.79 mm (average 1.71 mm) and were spherical and adhesive. Within 4 hours 35 minutes after fertilization, they reached the two-cell stage, and after 74 hours 10 minutes, the formation of the yolk sac began. At 106 hours post-fertilization, a caudal fin appeared at the tail tip. Hatching began at 526 hours, and the larvae developed with the yolk sac positioned just behind the eyes. The newly hatched larvae had both the mouth and anus open. Melanophores appeared inside the lower jaw and around the tail on the third day after hatching. By the 16th day after hatching, most of the yolk was absorbed, and melanophores were visible in the head region. Finally, on the 63rd day after hatching, the head region significantly developed, and the body shape and mouth were similar to those of an adult fish, signifying the transition to the juvenile stage. This study will serve as valuable data for aquaculture techniques related to the conservation and restoration of fish species based on the hatching and juvenile morphology of Liparis tanakae.