• 한국수산과학회지
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• 제54권5호
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• pp.585-595
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• 2021

Even though most of aquatic animal pathogens are considered opportunistic and many pose a low direct risk to personnel, all personnel working with aquatic pathogens and facilities using these organisms must comply with the regulation to prevent the release of the pathogen into the environment and causing disease in aquatic animals. First of all, in order to establish a biosafety system for aquatic pathogen, the list of microorganisms that can infect aquatic animals and humans should be drawn up according to the microorganisms encountered within national boundaries. Second, risk assessment guideline for diseases of livestock and aquatic environment is desperately needed. Third, microorganisms should be classified into risk group based on their potential impact on human and aquatic environment. Fourth, facilities handling aquatic pathogens should ensure that these pathogens are securely contained and safely handled for experimental or commercial development purposes. In conclusion, classification is based on the pathogenicity, mode of transmission and host range of the aquatic microorganisms, availability of effective preventative measures and treatments. Furthermore, risk group of aquatic pathogens should be correlated with physical containment facility requirements according to domestic characteristics.

• 한국수산과학회지
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• 제36권6호
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• pp.661-668
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• 2003

Performance of an airlift bioreactor (ABR) containing the immobilized microorganisms was evaluated in an integrated pilot scale recirculating aquaculture system stocked with Nile tilapia (Oreochromis niloticus) at an initial rearing density of $5\%$ and compared to a rotating biological contactor (RBC) for 40 days. The TAN concentration of rearing tank for ABR and RBC were maintained at $0.4\;g/m^3$ and $0.5\;g/m^3,$ respectively, The nitrite nitrogen was completely removed by the ABR. The ABR's aeration was more stable than the RBC's. On the whole, the feasibility of ABR as an aquacultural water treatment unit was recognized.

• 환경생물
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• 제20권3호
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• pp.189-196
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• 2002

The direct detection of intestinal pathogens and viruses often requires costly, tedious, and time-consuming procedures. These requirements developed a test to show that the water was contaminated with sewage-borne pathogens by assessing the hygienic quality of water based on indicator microorganisms whose presence indicates that pathogenic microorganisms may also be present. Various groups of microorganisms have been suggested and used as indicator microorganisms. Proposed and commonly used microbial indicators are total coliforms, fecal coliforms, fecal streptococci, Clostridium perfringens, heterotrophic plate count, bacteriophage, and so on. Unfortunately, most, if not all, of these indicators are not ideal because of the sensitivity and resistance to environment stresses and disinfection. However, the development of gene probes and PCR technology may give hope for the discovery of rapid and simple methods toy detecting small number of fecal pathogens in various environments.

• Applied Microscopy
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• 제34권2호
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• pp.103-111
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• 2004

수생식물 개구리밥(Spirodela polyrhiza)의 식물체 발달 과정에서 나타나는 미생물과의 상호관계를 주사전자현미경 및 세포학적으로 추적하여 연구하였다. 개구리밥은 부유성 식물로 분화 발달 초기부터 잠수부위에 여러 종류의 박테리아, 남조류, 규조류 등이 서식하였다. 미분화된 어린 식물체에는 성숙 발달한 식물체에 비해 미생물들이 낮은 빈도로 출현하였고, 성숙한 식물체에서는 특히 엽상체 하피에 가장 많은 미생물들이 서식하였으며, 그 다음으로는 점액성 물질이 층을 이루는 근관에 많이 관찰되었다. 반면, 신장 발달 중의 뿌리에는 일반적인 분포를 보였으며, 상피에는 미생물이 거의 분포하지 않는 양상을 보였다. 이들 미생물이 개구리밥 조직 내에 침입하여 식물체에 어떠한 영향을 미치는가를 조사하기 위해 엽상체, 연결사, 뿌리, 근관, 무성생식낭 등의 구조를 세포학적으로 추적한 결과, 어느 부위에서도 조직 내로 미생물이 침입하여 세포를 괴사시키거나 감염시키는 일은 거의 관찰되지 않았다. 그러므로, 개구리밥 식물체의 발달과정에 있어 미생물들은 어떠한 해를 주지 않는 것으로 추정된다. 이후 개구리밥에 서식하는 미생물의 질소고정치를 측정하여 그 기능을 식물체의 세포학적 측면과 접목시켜 연구하면 개구리밥과 미생물과의 상호관계가 공생적인지를 더 확실하게 밝힐 수 있을 것이다.

• Fisheries and Aquatic Sciences
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• 제6권3호
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• pp.135-139
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• 2003

During routine survey of Pacific oyster (Crassostrea gigas) collected from Tongyoung area in southern coast of Korea, histological examination revealed that a intracellular microorganisms infected the digestive gland of the oyster. They infected hepatopancreatic cells extensively. The size of intracellular microorganism was of 45 to 86nm in diameter and 200nm to more thar 500nm in length. They were pleomorphic. The morphological characteristic of intracellular microorganisms lacked cell wall and was bounded by the plasma membrane. They contained typical prokaryotic ribosomes and fibrillar DNA-like strands. No additional internal structure has been observed. Based on the lack of cell wall and the cellular localization, the intracellular microorganism is considered as a Mycoplasma-like organism.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.445-445
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• 2005

• 한국어병학회지
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• 제20권2호
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• pp.169-178
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• 2007

• 한국어병학회지
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• 제25권2호
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• pp.77-84
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• 2012

Various antibiotics, that could induce the appearance of resistant microorganisms, have been used for treatment or prevention of bacterial diseases in marine and ornamental fish. We determined and characterized the level of antibiotic-resistant bacteria and proportion of multi-drug resistant bacteria in intestinal microflora of both marine fish cultured in Korea and imported ornamental freshwater fish. For this the bacterial species and resistance to antibiotics were investigated in intestine of rock bream Oplegnathus fasciatus cultured in Korea and pearl gourami Trichogaster leeri imported from Singapore to characterise. Although the bacterial species were different, proportions of resistant bacteria to single antibiotics or multi-drug were higher in intestinal microflora of pearl gourami Trichogaster leeri imported from Singapore than in rock bream Oplegnathus fasciatus cultured in Korea. These results indicate that various antibiotics have been being used before trading without measures in the market of asian ornamental fishes, providing high risks for the emergence of multi-drug resistant bacteria.

• 한국수산과학회지
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• 제52권2호
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• pp.180-184
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• 2019

Aerobic bacteria, coliforms, Escherichia coli, and pathogenic bacteria were investigated in laver Porphyra sp. samples from various regions of Korea. The mean bacterial counts were $6.9{\pm}0.87log\;CFU/g$ (range 4.0 to 7.7) log CFU/g in dried laver, $2.83{\pm}4.36log\;CFU/g$ in roasted laver, and $4.93{\pm}1.43log\;CFU/g$ in seasoned laver. Coliforms were most abundant (mean count: $2.1{\pm}1.01log\;CFU/g$) in dried laver. No pathogenic bacteria, including Staphylococcus aureus, Salmonella spp. Vibrio parahaemolyticus, or Listeria monocytogenes, were detected in any of the samples. Aerobic microorganisms were the most diverse microorganisms in dried laver. Staphylococcus spp. were predominant, but S. aureus was not detected. Standardization of laver production is necessary to ensure a hygienic product because laver products are often ingested without heating or cooking, and the production process is simple.

• 한국어병학회지
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• 제31권1호
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• pp.41-48
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• 2018

흰다리새우양식에 있어 저면에서 생성된 황화수소($H_2S$)를 Bacillus속 미생물을 이용하여 저감이 가능한지 아래 3가지 균주들의 조합에 대해 시험하였다. 시험에 사용한 3가지 Bacillus속 균주들을 A시험군(B. subtilis + B. licheniformis), B시험군(B. licheniformis +B. amyloliquefaciens) 및 C시험군(B. subtilis + B. licheniformis + B. amyloliquefaciens)으로 구성하였다. 3가지 조합으로 시험균을 배양 한 뒤, 인위적으로 황화수소(3 mg/L)를 폭로하여 용존황화수소를 측정하였다. 그 결과, 시험군C가 용존황화수소를 초기에 저감하는 것을 측정하였다. 또한 시험군C를 배양하여 분리한 균체의 양을 달리하여 황화수소용액에 가했을 때 황화수소 감소능은 첨가한 균체의 양에 비례하여 증가하였다. 그러나 이 조건에서 최대량의 균체를 가하였을 때에도 시험군A 및 B는 황화수소 감소능을 발휘하지 못하였다. 용존황화수소가 흰다리새우에게 미치는 독성을 평가하기 위해, 황화수소(1-8 mg/L)를 폭로(매 1회/1일, 7일간 반복)하여 생존율을 측정한 결과 8 mg/L에서 가장 높은 누적치사율(20%)을 유발하였다. 흰다리새우 사육수에 시험군C(1 g/L)를 48시간 배양한 후 황화수소 1 mg/L에 폭로시키면서 흰다리새우 생존율을 14일간 지속 관찰한 결과 대조군에서 82.5% 시험군C를 가한 시험군에서는 97.5% 수준의 생존율이 관찰되었다. 그러므로 새우양식에서 3종의 Bacillus속 시험군C는 유해한 용존황화수소의 발생을 줄이고 나아가 흰다리새우 생산량의 증대를 가져올 수 있을 것으로 사료된다.