• 한국토양비료학회지
• /
• 제47권6호
• /
• pp.437-442
• /
• 2014

Foodborne illness due to the consumption of contaminated raw strawberries is a continuing food safety concern. This study investigated and evaluated contamination levels of bacteria on strawberries at farms stage to evaluate potential hazards associated with fresh strawberries. A total of 315 samples, 105 samples from 5 sampling sites (A to E) of 21 farms and 210 samples from 1 sampling site of 6 farms, was collected every month for four months and analyzed to enumerate aerobic bacterial counts, Coliforms/E. coli, Bacillus cereus and Staphylococcus aureus. In addition, the prevalence study of five pathogens (S. aureus, E. coli, E. coli O157:H7, Salmonella spp. and Listeria monocytogenes) was performed on each sample. Aerobic bacterial counts ranged from 0.48 to 6.36 Log CFU/g, with the highest bacterial cell counts recorded for D and E sites. Coliforms were detected in 71 samples (22.5%) with a minimum of 0.48 cfu/g and a maximum of more than 4 Log CFU/g. B. cereus was detected in 98 samples (31.1%) among total samples analyzed. S. aureus was detected in 2 samples with a minimum of 0.48 Log CFU/g and a maximum of 1.38 Log CFU/g. E. coli, E. coli O157:H7, Salmonella spp. and L. monocytogenes were not isolated from any of the samples. The microbial contamination levels of strawberries determined in this study may be used as the fundamental data for microbiological risk assessment.

• 한국식품위생안전성학회지
• /
• 제32권3호
• /
• pp.228-233
• /
• 2017

서양종 꿀벌의 일벌의 독을 채취하여 정제한 정제봉독에 대한 세균에서의 돌연변이 유발성 검색을 위하여 S. typhimurium의 히스티딘 요구성 균주 TA100, TA1535, TA98, 그리고 TA1537의 균주와 대장균 E. coli의 트립토판 요구성 균주인 WP2 uvrA를 이용해 복귀돌연변이시험을 실시하였다. 정제봉독은 부형제로 사용한 멸균생리식염수에 용해되었으며 모든 농도군의 조제물에서 침전은 관찰되지 않았으며, 정제봉독 조제물을 top agar와 혼합할 때 모든 농도군에서 혼탁이나 침전이 관찰되지 않았다. 대사활성계 적용 TA100, TA1535, TA98 균주에 대해 0, 1.5, 5, 15, 50, 150 및 500 µg/plate의 범위를 설정하고 미 적용시엔 0, 0.15, 0.5, 1.5, 5, 15 및 $500{\mu}g/plate$의 범위로 설정하였다. TA1537과 WP2 uvrA균주에 대한 농도 범위은 대사활성계 적용시엔 0, 5, 15, 50, 150, 500 및 1,500를 미 적용시엔 0, 1.5, 5, 15, 50, 150 및 500 µg/plate 범위로 설정하여 시험을 수행하였다. 그 결과 모든 시험균주에서 대사활성계 적용 여부에 상관없이 정제봉독 처리군의 평균 집락 수는 증가를 나타내지 않았으며, 양성판정 기준을 만족시키지 못하였다. 따라서, 정제봉독은 본 시험조건 하에 사용한 시험 균주에 복귀돌연변이를 유발하지 않는 것으로 사료되었다.

• 한국물환경학회지
• /
• 제32권3호
• /
• pp.271-280
• /
• 2016

The aim of this study was to analyze spatial and temporal patterns of bacterial pollution levels and the relationship between bacterial pollutants and environmental parameters at the main stream and tributaries of Nakdong River. Water quality data including total coliform and fecal coliform were compiled from a total of 50 monitoring sites (30 at the main stream and 20 at the tributaries) along with rainfall and discharge data for three consecutive years from 2012 to 2014. During the study periods, the geometric mean values of total coliforms and fecal coliforms in the main stream were 74 (22~465) CFU/100 mL and 8 (3~42) CFU/100 mL, respectively. The geometric mean values of total coliforms and fecal coliforms in the tributaries were 275 (36~5,145) CFU/100 mL and 6 (1~1,352) CFU/100 mL, respectively. High concentrations of fecal coliforms were observed at Gumi (M 10), Hyeonpung (M 19), Hapcheon (M 23), and Namji (M 25) in the main stream, whereas Gamcheon (T 6), Bakcheon (T 7), Geumho-gang (T 8), and Gyeseongcheon (T 16) were identified as pollution hot spots in the tributaries. Although bacterial pollution levels showed complex behavior across monitoring sites and time, the highest coliform concentrations were routinely observed in the monsoon season between July and September of each year, indicating that the pollution levels were strongly dependent on precipitation in addition to other physiochemical parameters. Statistically significant correlations were found between fecal coliform concentrations and precipitation (r=0.403, p<0.01), followed by SS (r=0.425, p<0.01), nutrient TP (r=0.388, p<0.01), organic matter COD (r=0.322, p<0.01), and PO₄-P (r=0.317, p<0.01) in the main stream in the order of correlation coefficient from high to low.

• 한국유기농업학회지
• /
• 제22권4호
• /
• pp.657-665
• /
• 2014

토마토 억제 재배 시 생산비를 절감하고 토마토의 수확시기를 앞당기며 잦은 경운에 의한 토양환경을 보호하고자 가지대목(EG203)을 활용한 딸기후작 토마토 무경운 재배법 연구를 실시하였다. 가지대목(EG203)을 사용하여 토마토 재배를 실시한 결과 풋마름병 발생은 무경운 재배에서 실생은 30%, 가지대목(EG203)은 0%였으며 경운 재배에서는 실생은 25%, 가지대목(EG203)은 0%였다. 가지대목(EG203)을 이용한 경운 및 무경운 재배에서 상품수량은 각각 2,693, 2,657 kg/10a로 유사하였으며 당도 및 경도도 차이를 보이지는 않았다. 따라서 딸기 후작 토마토 재배에서 풋마름병에 대한 안전성을 높이기 위해 가지대목(EG203)을 활용하여 접목을 실시하여야하며 가지대목(EG203)을 이용하여 재배할 경우는 경운과 무경운 재배의 차이가 나타나지 않으므로 경제성 및 환경적으로 무경운 재배가 유리할 것으로 판단된다. 토마토 정식 당일, 10, 20, 30일 후 전작물인 딸기를 제거한 결과 20, 30일 후 제거에서 초장과 절간장은 길었으나 다른 생육에서는 차이를 보이지 않았다. 상품수량은 정식 당일 제거한 것이 1,885 kg/10a로 30일 후 제거 1,678 kg/10a보다 12% 많았으나 전작물인 딸기의 제거 시기는 딸기의 생육과 가격을 토마토의 기대소득과 비교 경제성을 분석하여 결정하여야 할 것으로 생각된다.

• Journal of Korean Academy of Oral Health
• /
• 제41권1호
• /
• pp.22-27
• /
• 2017

Objectives: Dental plaque is composed of 700 bacterial species. It is known that some oral microorganisms produce porphyrin, and thus, they emit red fluorescence when illuminated with blue light at a specific wavelength of <410 nm. Porphyromonas gingivalis belongs to the genus Porphyromonas, which is characterized by the production of porphyrin. The aim of this study was to evaluate red fluorescence emission of some oral microorganisms interacting with P. gingivalis. Methods: Five bacterial strains (P. gingivalis, Streptococcus mutans, Lactobacillus casei, Actinomyces naeslundii, and Fusobacterium nucleatum) were used for this study. Tryptic soy agar medium supplemented with hemin, vitamin K3, and sheep blood was used as a growth medium. The fluorescence emission of bacterial colonies was evaluated under 405 nm-wavelength blue light using a Quantitative Light-induced Fluorescence Digital (QLF-D) camera system. Each bacterium was cultured alone and co-cultured in close proximity with P. gingivalis. The red/green (R/G) ratio of fluorescence image was calculated and the differences of R/G ratio according to each growth condition were compared using the Mann-Whitney test (P<0.05). Results: Single cultured S. mutans, L. casei and A. naeslundii colonies emitted red fluorescence (R/G ratio=$2.15{\pm}0.06$, $4.31{\pm}0.17$, $5.52{\pm}1.29$, respectively). Fusobacterium nucleatum colonies emitted green fluorescence (R/G ratio=$1.36{\pm}0.06$). The R/G ratios of A. naeslundii and F. nucleatum were increased when P. gingivalis was co-cultured with each bacterium (P<0.05). In contrast, the R/G ratios of S. mutans and L. casei were decreased when P. gingivalis was co-cultured with each bacterium (P=0.002, 0.003). Conclusions: This study confirmed that P. gingivalis could affect the red fluorescence of other oral bacteria under 405 nm-wavelength blue light. Our findings concluded that P. gingivalis has an important role for red fluorescence emission of dental biofilm.

• 한국자원식물학회:학술대회논문집
• /
• 한국자원식물학회 2010년도 정기총회 및 추계학술발표회
• /
• pp.18-18
• /
• 2010

Molecular insights on the role of plant growth promoting rhizobacteria (PGPR) in potato tuberization are reported in the present study. The PGPRwere isolated from the soil collected from potato fields of Highland Agricultural Research Centre, Pyeongchang, Korea and they were identified to the genus level based on the 16S rRNA sequence analysis. These PGPR were heat-killed, filtered and the filtrates were addedindividually at a concentration of $10^7\;cfu\;mL^{-1}$ in MS (Murashige and Skoog's) medium supplemented with 7% (w/v) sucrose to study their influence on in vitro potato tuberization. Tuber initiation occurred early in untreated control, while tuber growth was pronounced in case of PGPR treatments. The control explants showed tuber formation as a result of sub-apical swelling of stolons while several sessile tubers formed directly in the axils of nodal cuttings in case of PGPR treatments, which is an indication of strong induction for tuberization. Theexplants cultured on MS medium supplemented with bacterial isolate 6 (Bacillus firmus strain 40) showed highest average tuber yield (Ca. 12.56 g per treatment) after 30 days of culture, which was 3 folds increase over the untreated control. A significant increase in lipoxygenase (LOX1) mRNA expression and activity of LOX enzyme were also detected in the tubers induced on PGPR treatments as compared to untreated control. This LOX expression level correlated with increased tuber growth and tuber yield. Further studies focused on the role of bacteria cell wall components, growth regulators and signal molecules released by PGPR are under investigation to elicit clues for PGPR-mediated signal pathway controlling potato tuberization.

• Fisheries and Aquatic Sciences
• /
• 제5권1호
• /
• pp.1-4
• /
• 2002

The modulatory effects of oxytetracycline treatments at high concentrations on the infection potential of scuticociliates in cultured juvenile olive flounder (Paralichthys olivaceus) and density of the ciliates in culturing water were investigated. The groups bathed with 400 and 500 ppm of oxytetracycline showed significantly lower intensities of scuticociliates on the fish and considerably lower number of the ciliates in culturing water when compared with the control group. However, the intensity of scuticociliates on the fish in the group bathed with 300 ppm of oxytetracycline was not significantly different with that of the control group in spite of considerably lower number of scuticociliates in culturing water than in that of the control group. Although the intensities of scuticociliates on the fish intubated orally with 400 and 500 mg/kg of oxytetracycline were lower than that of the control group, there were no statistical significances. In contrast, the fish fed 300 mg/kg of oxytetracycline showed significantly lower intensity of scuticociliates when compared with other groups. The results of this study suggest that oxytetracycline treatments can modulate occurrence of scuticociliatosis in fish farms probably through change of bacterial density, damaging to scuticociliatosis and immuno-suppression of fish.

• Asian-Australasian Journal of Animal Sciences
• /
• 제7권1호
• /
• pp.137-145
• /
• 1994

Amino acid (AA) substituted diets had no influence on rumen levels of total volatile fatty acids (VFA), ammonia and ${\alpha}$-amino-N, but tended to increase molar proportions of isovalerate and counts of total viable AA utilizing and celluloytic bacteria in the rumen as compared with the control urea diet. The AA diets did not affect daily flow to the duodenum of dry matter (DM), organic mater (OM) and acid detergent fibre (ADF), and rumen digestibility of these nutrients. However, the AA diets, in particular the 10 essential AA (EAA) diet improved total digestibility of DM, OM and ADF by decreasing faecal output of these fractions. Although N flow to the duodenum and N retention were not affected with the dietary treatments, duodenal bacterial flow appeared to increase by the AA diets when it was estimated by means of 2,6-diaminopimelic acid (DAP) and nucleic acid-purine bases (PB) as markers. The results suggest that AA supplements to a urea diet could improve feed utilization by stimulating microbial activity and proliferation in the rumen but and increased microbial activity per se is not necessarily associated with improvement of feed conversion.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XIII)
• /
• pp.294-299
• /
• 2003

The growth of Bacteroides fragilis was inhibited by combination of natural products bearing antioxidative capacity and combined two, three and four kinds of them. Bacteroides fragilis was controlled by Paeonia Japonica, Corni Fructus, Theae Folium, Coptidis Rhizoma alone, and two mixed combinations of Paeonia japonica and Scutellaria Baicalensis George, Scutellaria Baicalensis George and Schizandrae Fructus, Schizandrae Fructus and Theae Folium, Schizandrae Fructus and Corni Fructus, Schizandrae Fructus and Crataegi Fructus, Paeonia japonica and Schizandrae Fructus, and three mixed combinations of Paeonia Japonica and Scutellaria Baicalensis George and Schizandrae Fructus, Paeonia Japonica and Scutellaria Baicalensis George and Crataegi Fructus, Paeonia Japonica and Scutellaria Baicalensis George and Corni Fructus, and four mixed combinations of Scutellaria Baicalensis George and Crataegi Fructus and Corni Fructus and Schizandrae Fructus, Scutellaria Baicalensis George and Crataegi Fructus and Corni Fructus and Theae Folium. As these combinations of natural products will activate some parts of body, theymay be applied to pharmaceutical applications, functional foods, antiaging tea, alsoexpected to control bacterial growth for fermentative beverage bearing multifunction.

• 한국생물공학회:학술대회논문집
• /
• 한국생물공학회 2003년도 생물공학의 동향(XII)
• /
• pp.195-200
• /
• 2003

The growth of S. aureus was inhibited by combination of natural products bearing antioxidative capacity and combined two, three and four kinds of them. S. aureus was controlled by Paeonia Japonica, Galla Rhois, Geranii Herba, alone, and two mixed combinations of Paeonia japonica and Scutellaria Baicalensis George, Paeonia japonica and Theae Folium, Paeonia japonica and Chelidonium Majus L, Paeonia japonica and Geranii Herba, Paeonia japonica and Schizandrae Fructus, and three mixed combinations of Paeonia Japonica and Scutellaria Baicalensis George and Geranii Herba, Paeonia Japonica and Scutellaria Baicalensis George and Chelidonium Majus L., Paeonia Japonica and Scutellaria Baicalensis George and Theae Folium, and four mixed combinations of Scutellaria Baicalensis George and Chelidonium Majus L. and Theae Folium and Schizandrae Fructus, Paeonia Japonica and Scutellaria Baicalensis George and Chelidonium Majus L. and Schizandrae Fructus, Scutellaria Baicalensis George and Geranii Herba and Theae Folium and Schizandrae Fructus. As these combinations of natural products will activate some parts of body, they may be applied to pharmaceutical applications, functional foods, antiaging tea, also expected to control bacterial growth for fermentative beverage bearing multifunction.