• Journal of Mushroom
• /
• v.9 no.4
• /
• pp.135-138
• /
• 2011

'Gonji-2ho' a new variety of oyster mushroom, fitting for the bag culture, was bred by mating between monokaryons isolated from GMPO35338 and Jangpug. In the major characteristics of fruit body, the pilei were thick and dark-gray and the stipes were thick and long with softness. It was great in elasticity and cohesivness of tissue as compared to Suhan-1ho. The optimum temperature for the mycelial growth was around $26{\sim}29^{\circ}C$ and for the pinheading and growth of fruit body was around $14{\sim}18^{\circ}C$. In the bag culture, it was required around 20 days at incubation period and 5 days at primordia formation. The fruit body was grown vital and uniform. The yields were 323.3g/kg bag. This variety has high yielding capacity, cultivation stability and the resistance to the bacterial brown blotch disease.

• Journal of agricultural medicine and community health
• /
• v.45 no.2
• /
• pp.69-78
• /
• 2020

Purpose: This study was conducted to provide the results of the epidemiological investigation for outbreak of Clostridium perfringens enteritis among students at a college in Sejong City. Methods: This investigation was performed between May 25 and May 28, 2018. The Sejong City public health authority received a complaint which was about 40 university students experienced vomiting or diarrhea. We immediately set up an epidemiological investigation team and conducted a field epidemiological investigation. Results: The overall incidence was 86 out of 153 (56.2%). The estimated risk exposure time was 12 o'clock on the previous day, and the cause was contaminated during distribution and storage of the lunch box provided for lunch on the day of the athletic competition, with 13 hours of average incubation period. The outbreak was closed on May 28, and the identified pathogen was Clostridium perfringens. Conclusions: It was proposed that food poisoning by Clostridium perfringens was likely and contaminated during group meal.

• Korean Journal of Environmental Biology
• /
• v.33 no.1
• /
• pp.83-91
• /
• 2015

This study is measured the change of chlorophyll-${\alpha}$ concentration and phytoplankton density, the grazing rates (GR) and pseudofaeces production (PFP), by grazing of freshwater apple snail, Pomacea canaliculata, to investigated that the snails are able to control of phytoplankton bloom. The experiments are performed to evaluate the GR and PFP at different conditions such as incubation time (0, 2, 4, 6, 8, 10 and 12 hr), shell height (1.0 to 4.0 cm, n=108), snail density (1, 1.5, 2.5, 3.5 and 5 indiv. $L^{-1}$) and food concentration (200, 400, 600, 800 and $1000{\mu}g$ $L^{-1}$). Regarding feeding time, the highest GR (2.5 L. $gAFDW^{-1}h^{-1}$) and PFP (15.3 mg $AFDW^{-1}$) showed at 4 hr after snail stocking, respectively. The snail, smaller than 1.5 cm in body size, showed the highest of GRs (2.54 L. $gAFDW^{-1}h^{-1}$) for the initial period (2 hr of stocking), compared to those greater than 1.5 cm, which showed a stable FR, higher than 0.099 L. $gAFDW^{-1}h^{-1}$. Upon snail density effect, the density of 5 indiv. $L^{-1}$ induced the most effective inhibition on phytoplankton biomass with the highest PFP. On the food concentration, the highest GR (0.54 L. $gAFDW^{-1}h^{-1}$) and PFP (8.5 mg $gAFDW^{-1}$) were induced at the level of $600{\mu}g$ $L^{-1}$, respectively. We checked that it is possible to control of phytoplankton bloom by the grazing of apple snail as well as Reeve. However, it required a through research for the remove of pseudofaeces and 2nd problem by the decomposition of the organic materals.

• KSBB Journal
• /
• v.7 no.2
• /
• pp.118-125
• /
• 1992

Most of cosmetics are emulsion-type products which contain the sources of nutrition, i.e., vegetable oil, mineral oil and carbohyrate etc.. These additives are usually very susceptible to the contamination by microorganisms. The purpose of this study is to obtain the data necessary not only to prevent dermalopathia occurred by microbials but also to maintain the quality. In this experiment we observed the growth of P.aeruginosa in the cosmetics with or without antiseptics so as to prevent contamination. During the contamination period, the phase became unstable and creaming phenomina was happened together with some discoloration and bad smell. The pH of cosmetic was decreased from 7.6 to 6.0 and the concentration was increased from 1.443 to 1.453 in terms of refractive index during 40 days incubation. By adding antiseptics to the cosmetics, the number of P. aeruginosa from the challenge test method were decreased from $10^8$ cell/ml to $5{\times}10^3$ cell/ml. For the antibacterial effect against P. aeruginosa, p-hydroxy benzoic acid propyl ester in phosphoric acid buffer solution showed the best result.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.2
• /
• pp.249-254
• /
• 2004

Effect of mulberry tree powders on the antioxidant activity of submerged -liquid culture of mushrooms was investigated. Agaricus blazei (AB), Hericicum erinacium (HE), Pleurotus ostreatus (PO), Phellinus linteu (PL) and Paecilomyces japonicus (PJ) were cultured in a shaking incubator (200 rpm, $25^{\circ}C$) for 7 days in culture media: 1) basal medium (BM) and 2) BM+1% mulberry tree powders (BMM). Hot water extracts from the submerged-liquid cultures of mushrooms and BMM were freeze-dried for the measurement of antioxidant activity, of which reaction mixture (25 mL: 10 mL of 0.2 M sodium phosphate buffer, pH 8.0; 4.5 mL distilled water; and 10.5 mL ethanol) contained 275 $\mu$mol linoleic acid and one mg test sample. The reaction mixture was incubated in a shaking incubator (200 rpm, 4$0^{\circ}C$) for 16 days. Peroxide value (POV) was measured for a period of over 16 days, and malonaldehyde (MA) was determined only for samples from the day 16 of incubation. Mycelial weight of mushroom strains cultured in BMM was greater than BM. The antioxidant activities of AB-cultured in BW (AB-BMM) and HE-cultured in BMM (HE-BMM) were superior to those of other mushroom strains-cultured in BMM or BM and of BMM. These results suggest that mulberry tree powders enhance the antioxidant activity of submerged-liquid culture of mushroom strains. The AB-BMM and HE-BMM were the most active cultures.

• Journal of Environmental Health Sciences
• /
• v.46 no.5
• /
• pp.525-531
• /
• 2020

Objectives: This study was performed to identify the epidemiological features of a food poisoning outbreak in a company cafeteria located in Chungcheongnam-do Province, Korea in June of 2020 and to suggest preventive measures for a similar incidence. Methods: A total of 84 patients with acute gastroenteritis were examined. Environmental samples were obtained from 16 food handlers, six food utensils, 135 preserved foods served over three days and nine menus, and six drinking water samples. These are analyzed to detect viruses and bacteria. Results: Ninety-four out of the 402 people who were served meals (23.4%) predominantly showed symptoms of diarrhea, and the number was over 3 times. Among the 84 patients under investigation, 17 cases (20.2%) were positive for Enteropathogenic E. coli (EPEC) and 18 cases were positive for Clostridium (C.) perfringens (21.4%). Based on the investigation, it was concluded that the main pathogens were EPEC and C. perfringens. For EPEC, it was detected in three of the food service employees and in the preserved food and curry rice. The results of pulsed field gel electrophoresis indicate that all EPEC cases are closely related except for one food service employee. Assuming that isolated EPEC originated from the preserved food, the incubation period is about 25 hours. The origin of the C. perfringens was not determined as it was not detected in the food service employees or environmental samples. Conclusions: This case suggests that food provided in group food service centers must be thoroughly managed. In addition, identifying the pathogens in preserved food is very important for tracing the causes of food poisoning, so food must be preserved in an appropriate condition. To prevent similar food poisoning cases, analyzing cases based on epidemiological investigation and sharing the results is needed.

• Research in Plant Disease
• /
• v.16 no.3
• /
• pp.279-284
• /
• 2010

Clubroot caused by Plasmodiophora brassicae is a widespread disease that causes serious problems in many brassica growing areas. To establish more simple and reliable clubroot screening method of Chinese cabbage to P. brassicae using soil-drenching inoculation, the development of clubroot on Chinese cabbage according to several conditions such as soil type, inoculum concentration of P. brassicae GN-1 (race 9), plant growth stage and incubation period was studied. In a commercial horticulture nursery media soil (CNS), disease severity of the seedling according to inoculum concentration increased in a dose-dependent manner, but did not in mixture of CNS and upland soil (1:1, v/v). To facilitate and acquire precise result of resistance screening of Chinese cabbage to clubroot, 10-day-old seedlings should be inoculated by drenching the spore suspension of P. brassicae to give inoculum density of $4.0{\times}10^8$ spores/pot. To develop the disease, the inoculated seedlings were incubated in a growth chamber at $20^{\circ}C$ for 3 days, and then cultivated in a greenhouse ($25{\pm}5^{\circ}C$) for five weeks. Under the optimum conditions, 25 clubroot-resistant (CR) and 3 clubroot-susceptible (CS) cultivars were tested for resistance to P. brassicae. All CR cultivars showed very clear resistance response, on the other hand all CS cultivars severly infected with the pathogen. The results suggest that this method is efficient screening method of Chinese cabbage for resistance to clubroot disease.

• The Korean Journal of Mycology
• /
• v.47 no.4
• /
• pp.373-383
• /
• 2019

We investigated the effect of different media components on the characteristics and productivity of Lentinula edodes cultivated in sawdust. Ten substrates were used for this study. Soybean and cotton seed meal were unsuitable substrates as fungal mycelia did not grow to maturity during the incubation period. Lentinula edodes (NIFoS culture number 2462) was grown on the ten substrates, and soybean hull, mixed medium, cotton seed hull and corn grain showed greater effect on the productivity than wheat bran. However, wheat bran induced higher productivity in NIFoS 2778 than the other substrates. Sawdust medium with soybean meal produced smaller fruiting bodies than the other substrates. In contrast, corn meal media produced larger mushrooms than the other substrates. The external characteristics of the mushrooms varied based on the substrates upon which they were grown. This is not surprising given that the substrates differed with respect to carbohydrate and protein content, e.g., cotton seed and soybean meal contained a higher crude protein and crude ash than the other substrates tested.

• Journal of The Korean Association For Science Education
• /
• v.30 no.8
• /
• pp.933-952
• /
• 2010

This study aims to characterize debate on a socio-scientific issue in the Internet and to provide implications from a postmodernist perspective. This study concentrates on disentanglement of the complex relationship among society, economy, politics and science in an issue and characterization of the given text centering on its originality, the relationship between writer and reader, and the purpose of utterance. Sixty-six most read articles on a web message board were chosen and analyzed as a typical case of a socio-scientific issue in the internet. In them, five scientific disputes were identified: the cause of mad cow disease (MCD), specified risk material and the incubation period, the cause of new variant Creutzfeld-Jakob disease (vCJD), vulnerability of vCJD and the relation of Alzheimer and vCJD in American patients. Each argument is intertwined with social, economic and political problems such as its impact on the domestic beef market, feeding environment of imported cattle and the retaliation against denial of importation. With regard to originality, it is found that the originality of an author is weakened but communal through repetitive quotation of 'Peom', cutting and pasting, and engagement of readers with their comments. Furthermore, in order to close the gap between writer and reader, identity and personal narrative of the writers are often introduced into their writing. In terms of purpose of utterance, these are intended to deliver one's feelings or facilitate human behavior rather than inform through verification of a principle.

• Korean journal of food and cookery science
• /
• v.11 no.4
• /
• pp.379-385
• /
• 1995

The effect of low concentrations of ethanol (3-7％, v/v) in tryptic soy broth (TSB) as an antibacterial agent against Listeria monocytogenes was tested at -20, 5, 35, 45, 50 and 55$^{\circ}C$. Increasing concentrations of ethanol progressively inhibited initial growth of L. monocytogenes at 35$^{\circ}C$. Growth occured at 5％ ethanol, but only after a prolonged lag period. The number of viable cells of L. monocytogenes declined during incubation at 7％ ethanol. TSB containing 3-7％ ethanol was inoculated with 10$\^$5/-10$\^$6/ cells/$m\ell$ or L. monocytogenes and incubated at low temperatures (5$^{\circ}C$, -20$^{\circ}C$). In the presence of 3％ of ethanol at 5 or -20$^{\circ}C$, bacterial growth was inhibited more than 90％ of control cells. TSB containing 3-7％ ethanol was inoculated with 10$\^$6/-10$\^$7/ cells/$m\ell$ of L. monocytogenes and incubated at high temperatures (45$^{\circ}C$, 50$^{\circ}C$, 55$^{\circ}C$). Decrease in viability of the cells incubated at 45 or 50$^{\circ}C$ was slow and the survival of L. monocytogenes was not affected so much in the presence of 3％ of ethanol. The viability of L. monocytogenes was decreased with increasing concentration of ethanol and temperature. Decimal reduction times (D-values) based on tryptic soy agar plates at 55$^{\circ}C$ were 20.1, 12.6, 7.4 and 4.2 min in 0, 3, 5 and 7％ ethanol, respectively.