• Journal of Food Hygiene and Safety
• /
• v.32 no.2
• /
• pp.129-134
• /
• 2017

Diarrheagenic Escherichia coli is now recognized as an important cause of diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome (HUS) worldwide. E. coli were isolated from 80 of 356 (22.5%) chicken and chilled chicken products in Korea. Fifteen virulence genes specific for pathogenic E. coli, including Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC) and enteroaggregative E. coli (EAEC), were examined by multiplex PCR. STEC virulence markers were detected for eaeA (20.0%), escV (21.3%), stx1 (3.8%), ent (2.5%), EHEC-hly (1.3%), stx2 (1.3%), EAEC virulence marker (astA) was detected in 32.5%. ETEC and EIEC were not detected. STEC serotypes O152, O1, O116, O26, O25, O119 and O153 were found in chicken samples. This suggests the importance of diarrheagenic Escherichia coli control in raw chicken and chilled chicken food for food safety.

• Korean Chemical Engineering Research
• /
• v.50 no.5
• /
• pp.825-829
• /
• 2012

In this study, we investigated NO oxidation characteristic that depends on available chlorine concentration and temperature of seawater which is treated by un-divided electrolysis. Reactant gas passed through bubbling reactors which is filled with electrolyzed water and then NO concentration change was analyzed. In the closed-loop electrolysis system, concentration of available chlorine increased with electrolysis time. The higher oxidation rate of NO to $NO_2$ was obtained with the higher concentration of available chlorine. Oxidation of NO was fast when temperature of electrolyzed water was high, in the case of same concentration of available chlorine.

• Journal of the Society of Naval Architects of Korea
• /
• v.51 no.6
• /
• pp.451-458
• /
• 2014

The purpose of this study is to compare the economics between a diesel propulsion vessel and a LNG fuel propulsion vessel through the analysis of the present value using the LCC(Life Cycle Cost) method. This study is also to judge the economics for long-term operation of a LNG fuel propulsion vessel as a result of analysis about the equivalent uniform annual cost. In particular, LCC method was strengthened by sensitivity analysis based on combined interest rate which is considering discount rate and inflation rate simultaneously.

• 한국해양학회지
• /
• v.22 no.4
• /
• pp.271-278
• /
• 1987

Attempts were made to elucidate the responsible toxin in mussel Mytilus sp. which caused a food pisoning incident in March 1986 in Pusan, Korea. Two persons were dead and 15 persons intoxicated in the incident. The mid-gut glands of the mussel collected were extracted with dichlorlmethane, filtered through a Diaflo ulteafiltration membrane, and then purified by chromatography on Bio-Gel P-2 and Bio-Rex 70. The toxic fractions obtained were analysed by electrophoresis, TLC and ion-pairing reversed phase HPLC analyses. The results showed that the fractions contained GTW$\_$1-4/ as the major component, along with neoSTX, PX$\_$1,2/ as the minor. It was concluded from these results that the causative mussel toxin of the above food poisoning was PSP.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.2
• /
• pp.230-237
• /
• 2012

Engine makers are lately interested in the gas engine development as the alternative for diesel engine in order to cope the rise of oil price and the environmental regulation. So, STX has developed the 1.6MW gas engine which was converted from 22HLX diesel engine. The gas engine developed with precombustion chamber, which has good performance of 21bar BMEP at engine speed 1000rpm and low $NO_X$ emission of 50ppm at 15% oxygen composition, has been developed recently. Especially, it has a good thermal efficiency of 45% and a reduction efficiency of green house gas($CO_2$) emission of 25% than a conventional diesel engine.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.5
• /
• pp.731-737
• /
• 2013

Seventy-four Shiga toxin-producing Escherichia coli (STEC) isolates belonging to the serotype O91:H21 were isolated from 1,643 asymptomatic human carriers in a STEC outbreak at Gwangju in Korea. Although the isolates did not cause any symptoms, all of them produced Shiga toxins 1 (Stx1) and 2 (Stx2). In order to determine why these strains cause no symptoms, we explored the differences in virulence potential between the asymptomatic STEC O91:H21 isolates and symptomatic STEC O91:H21 strains (ATCC 51435 and ATCC 51434). The asymptomatic STEC O91:H21 isolates showed strongly reduced cytopathic effects compared with the symptomatic strains when intact bacterial cells were used as an inoculant. Moreover, we found a reduced adherence phenotype when testing asymptomatic strains on HeLa cells. Real-time quantitative PCR results suggest that transcriptional repression of the genes encoding type-1 fimbriae occurs in the asymptomatic isolates but not in the symptomatic strains.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.71-76
• /
• 1998

Tissue biosensor for mearsuring sodium channel blockers, such tetrodotoxin(TTX), saxitoxin (STX) and paralytic shellfish poisoning(PSP) consisted of frog bladder membrane, and $Na^{+}$ electrode. The proposed biosensor was applied to determine Chinese drug and dry or wet Porphyra yezonesis $Na^{+}$ channel blockers below the detection limit of the standard mouse bio-assay while the observed detection limit didn't cause human poisoning. The proposed biosensor system may be used for future $Na^{+}$ channel blockers monitoring within the marine environment.

• 한국해양학회지
• /
• v.24 no.2
• /
• pp.79-83
• /
• 1989

Attempts were made to analyze the toxin composition of the toxic mussel Mytilus edulis galloprovincialis which were collected from aquaculture pond in Apr. 1988 in Hachung, Koje, southern Korea. The toxins were partially purified from the ethanolic extract of the mussel digestive glands by activated charcoal and Bio Gel P-2 column chromatography. HPLC analysis demonstrated that the toxin consisted mainly of gonyautoxin 1-4 (GTX 1-4), along with trace amounts of saxitoxin (STX) and protogonyautoxin 1-2 (PX 1-2).

• Journal of Microbiology and Biotechnology
• /
• v.26 no.12
• /
• pp.2060-2065
• /
• 2016

Characteristics of E. coli O157:H7-specific infection bacteriophages (O157 coliphages) and broad-host-range bacteriophages for other E. coli serotypes (broad-host coliphages) were compared. The burst sizes of the two groups ranged from 40 to 176 PFU/infected cell. Distributions of the virulence factors stx1, stx2, ehxA, and saa between the two groups were not differentiated. Broad-host-range coliphages showed lower stability at $70^{\circ}C$, in relation to O157 coliphages. However, O157 coliphages showed high acid and ethanol tolerance by reduction of only 22% and 11% phages, respectively, under pH 3 and 70% ethanol for 1 h exposure. Therefore, these results revealed that the O157 coliphages might be more stable under harsh environments, which might explain their effective infection of the acid-tolerant E. coli O157:H7.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2003.05a
• /
• pp.225-230
• /
• 2003

Many port states such as New Zealand, the USA, Australia and Canada have strict regulations to prevent ships which arrive in their port from discharging polluted ballast water which contain harmful aquatic organisms and pathogens. They are notified that transfer of polluted ballast water can cause serious injury to public health and damage to property and environment. For this reason, they perceived that the ballast exchange in deep sea is the most effective method, together with submitting the ballast management plan which contains the effective exchange method, ballast system and safety consideration. In this study, we make an effort to develop optimum ballast water exchange management and in result of that, it provide more convenient and stable process for preparing ballast water management plan.