• Korean Journal of Microbiology
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• v.53 no.1
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• pp.29-38
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• 2017

In this study, we investigated the phylogenetic diversity of the bacterial community and isolation of extremely halophilic bacteria using culturomics in a gray solar saltern. The number of bacterial living cells, enumerated in a gray solar saltern by direct fluorescence microscopy was three to four orders of magnitude greater than those enumerated by plate counts, suggesting the distribution of 'viable but non-culturable bacteria'. The biodiversity of bacterial communities in a gray solar saltern was investigated by pyrosequencing, 1,778 OTUs of bacteria were comprised of 18 phyla 46 classes 85 orders 140 families 243 genera with 6.16 diversity index. Archaea communities were composed of 3 phyla 6 classes 7 orders 7 families 38 genera with 4.95 diversity index from 643 OTUs. Totally 137 isolates were isolated by 59 different cultural methods based on culturomics considering culture media and conditions suitable for the growth of extremely halophilic bacteria. Phylogenetic analyses of extremely halophilic isolates based on 16S rRNA gene sequences, extremely halophilic isolates were composed of 4 phyla and 11 genera. Haloterrigena and Haloferax can be successfully isolated from culturomics. These culturomics were effective methods for collection of diversity of extremely halophilic bacteria.

• Korean Journal of Poultry Science
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• v.16 no.3
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• pp.175-192
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• 1989

A total of 9, 012 cases was submitted for diagnosis of chicken diseases to Veterinary Research Institute, Rural Development Administration from domestic chicken farms during 18 years from 1971 to 1988. Of them, 6, 181 cases diagnosed as the infectious disease were investigated for the detection rate of infections on basis of you, season , and chicken age. The results obtained were summarized as followings：1. Detection rate or the infections was lowest as 49.3% in the year 1973, and highest as 78.6% in 1985 (average 68.6%). 2. Of infections detected, bacterial diseases were most frequent (32.6%), and followed in order by viral (26.3%), parasitic (7.7%), and fungal diseases (2.1%) in geneal. 3. The most frequently detected bacterial diseases in order of prevalence were mycoplasmosis (8.8%), colibacillosis (8.5%), and staphylococcosis (5.8%), and followed by salmonellosis pullorum disease , yolk sac disease, and salpingitis (0.8-1.5%). 4. In viral diseases, 7.5% of infections detected was lymphoid leukosis and 7.2%-Marek's disease, 4.4%-Newcastle disease, 2.0%-infectious laryngotracheitis, 1.7%-infectious bursal disease, and 1.0%-avian encephalomyelitis, while detection rate of infectious bronchitis, egg drop syndrome '76, and inclusion body hepatitis was less than 1.0%, respectively. 5. The most prevalent parasitic disease was coccidiosis (4.5%), followed by ascariasis (1.4%). The detection rate of other parasitic diseases including leucocytozoonosis, black head , heterakiasis, and ectoparasitosis was very as 0.2-0.7%, respectively： In fungal diseases, 2.0% of infections was detected as aspergillosis, and followed by candidiasis (0.1%). 6. Detection rate of the infections on basis of season was somewhat higher in summer. (27.7%), and autumn (27.7%) than in winter (23.5%), and spring (21.5%) in general. In bacterial, viral, and fungal diseases, there were the similar tendencies of detection rate as in infections, while parasitic diseases were much highly detected in summer (34.3%), and autumn (39.5%) than in any other season. 7. Among bacterial diseases colibacillosis was most frequently detected in summer, and staphylococcosis in autumn. In detection rate of viral diseases, Marek's disease, infectious laryngotracheitis, and infectious bursal disease was highest in summer, lymphold leukosis, fowl pox and egg drop syndrome '76 in autumn, and infectious trachitis in winter, repectively. The majority of important parasitic diseases including coccidiosis were highly detected in summer and autumn. 8. On basis of chicken age, detection rate of infections were highest in chicken of growing period between 30 and 150 days of age (41.4%), and followed by 35.3% in laying chicken over 150 days of age, and 17.3% in chicken of brooding age under 30 days of age. Bacterial, and parasitic diseases were most frequently detected in chicken of growing period, viral diseases in chicken of growing, and laying period as nearly equal rate of detection, and fungal diseases in chicken of brooding age.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.32-32
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• 2002

본 연구는 인공수정용 액상정액을 생산하는 돼지 AI 센터의 종모돈으로부터 채취한 정액내 세균 감염정도를 조사하고 감염율이 높은 세균에 대한 항생제 감수성을 조사하기 위하여 시도되었다. 3개 AI 센터의 원정액내 세균수 (cfu × 10²/㎖)는 각각 8.2±28.8(1 -100), 18.2± 20.0(5-48) 및 33.1±62.l(4-173)로서 평균 23.8±38.l 이었고 AI 센터간, 개체간에 변이 가 컸다. 감염 세 균의 특성은 간균 74%, Gram stain(＋)균 60%, catalase 생산 (＋)균 100% 및 oxidase activity (＋) 균 98%였으며 센터간에 다소 차이가 있었다. 정액샘플내 감연빈도가 높은 세균은 Bacillus sp(조사시료의 75.0%), Pseudomonas sp(67.9%), Proteus sp(53.8%), Staplhylococcus sp(53.6%), E. coli(l5.4%), Klebsiella sp(15.4%), Enterobacter sp(7.7%) 순이었으며 전체 감염세균 종류중 이들 세균의 비율은 각각 25.6%, 20.9%, 16.3%, 18.6%, 4.7% 및 2.3%였다. 액상정액에서 보존 2일과 6일의 세균수 (cfu×10²/㎖)는 2.4± 2.7과 44.0±44.6이었다. 항생제 감수성은 Corynebacterium sp의 경우는 8종 항생제 중 3종 (Streptomycin, polymyxin B, erythromycin)에서 저항성을 나타냈다.(농림기술개발사업 연구결과의 일부)

• Korean Journal of Microbiology
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• v.37 no.2
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• pp.114-119
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• 2001

Many isolates from different forest soil layers did not show appreciable growth on full strength of the conventional nutrient broth (NB medium) but grow on its 100-fold dilution (DNB medium). These isolates were divided into four types according to organic nutrient concentration in the growth medium from $1^{-1}\;to\;10^{-4}$dilution of normal NB medium. Oligotrophic bacteria were type II and type IV which grew in $10^{-4}$ dilution of NB (1 mg C/l) medium. Sixty strains were isolated for obligate oligotrophic bacteria. Chemotaxonomic and phylogenetic characteristics of eleven isolates of acetylene-reducing (nitrogen-fixing) oligotrophic bacteria from forest soil were investigated. They showed similar characteristics: the cellular fatty acid mainly consisted of straight-chain unsaturated $C_{18:1}$ (60-84% of total fatty acids). Ubiquinone Q-10 and a high guanine plus-cytosine content(61-64 mol%) were found. Eleven isolates of nitrogen-fixing oligotrophic bacteria were found to be closely related by full 16S rDNA sequence simility and many common taxonomic traits. Analysis of full 16S rDNA sequences of eleven isolates indicated that they were more closely related to Bradyrhizobium (similarity values: 98.1-98.8%), Agromonas, Nitrobacter, and Afipia.

• Pediatric Infection and Vaccine
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• v.24 no.3
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• pp.160-167
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• 2017

Purpose: Because children with asplenia have an increased risk of fulminant infection associated with a high fatality, chemoprophylaxis, and vaccinations against encapsulated bacteria are recommended. However, there have been few reports of the burden of severe bacterial infection and the current status of chemoprophylaxis and immunization among children with asplenia in Korea. Methods: We conducted a retrospective study including children with asplenia who were treated at our institute between January 1997 and December 2016. Results: From a total of 213 children with asplenia, 114 (53.5%) had congenital asplenia and 58 (27.2%) had functional asplenia. The remaining 41 (19.3%) had acquired asplenia with the median age at splenectomy being 12.2 years (range, 5.0 to 16.9 years); the most common cause of splenectomy was hereditary spherocytosis (39.0%). The chemoprophylaxis rate was 16.4%. The immunization rates were 44.1% for pneumococcus, 53.0% for Haemophilus influenzae type B, and 10.7% for meningococcus. The incidence of invasive bacterial infection among children with asplenia was 0.28/100 person-year; a total of six episodes (2.8%) were observed in five patients with congenital asplenia and one patient with functional asplenia. The median age for these infections was 15 months (range, 4 to 68 months). Five of the six episodes were bacteremia, and the other was meningitis. The most common pathogen was Streptococcus pneumoniae (n=3), followed by H. influenzae (n=1). Three of the six patients (50.0%) died, all of whom had pneumococcal bacteremia. None of the six had chemoprophylaxis or proper vaccinations. Conclusions: Although there is an increased risk of a severe infection proper vaccinations and chemoprophylaxis are still lacking. Physicians should be encouraged to implement appropriate chemoprophylaxis and immunizations for patients with asplenia.

• KOREAN POULTRY JOURNAL
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• v.47 no.2
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• pp.103-107
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• 2015

국내 축산업은 구제역, AI 등 법정전염병 발생은 물론 각종 호흡기성 및 세균성 질병이 끊임없이 발생해 농가피해가 심하고 식품의 안전성을 위협받고 있다. 또 다자간 FTA 체결로 값싼 외국산 축산물 수입량이 증가함에 따라 내 우외환의 홍역을 앓고 있는 실정이다. 축산업이 국내외적으로 어려운 시기에 경쟁력을 강화하기 위해서는 생산성 향상을 통한 생산비 절감과 함께 사육환경을 개선해 안전한 식품을 공급하는 동물복지형 친환경축산이 그 대안으로 평가 받고 있다. 이러한 시대적 요청을 선도하기 위해 동물복지형 친환경축산 발전에 기여하는 천연물 및 유익 미생물을 통해 질병, 환경 및 사료를 효과적으로 관리하여 농가소득 증대를 꾀하고, 나아가 축산 경쟁력 제고에 기여할 수 있는 친환경 제품의 개발에 박차를 기하는 업체를 방문하였다.

• 월간낙농육우
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• v.18 no.11 s.199
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• pp.76-76
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• 1998

최근 제주도의 한우 및 경기도, 강원도, 충청도 일부지역 젖소에서 유$\cdot$조산 발생이 부루세라 백신접종과 개연가능성이 있으나, 소의 유$\cdot$조산 발생원인은 세균성, 바이러스성, 원충성 등 그 요인이 매우 다양하여 원인규명이 쉽지 않은 실정입니다. 특별대책반에서는 정확한 발생 원인규명 중에 있으나 농가의 우선 예방치료 조치로서 향균제 치료 및 철저한 소독 등을 통하여 피해가 확산되지 않도록 예방치료를

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.10a
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• pp.117-118
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• 2000

매년 많은 식중독 사고가 보고되고 있는데, 특히 우리나라에서는 생선의 소비량이 많기 때문에 Salmonella 다음으로 Vibrio에 의한 식중독 사고가 높은 것으로 보고되고 있다. 이러한 세균성 식중독은 일반적으로 미생물이 숙주세포에 침입을 해야 하는데, 이를 위해 우선적으로 숙주세포 표면의 여러 단백질 층을 분해해야 한다. 이때 작용하는 단백질 분해효소가 병원성에 직ㆍ간접적으로 관여된다고 생각되고 있으며, 비브리오균이 생산하는 여러 가지 단백질 분해효소가 인간이나 어류의 병원성에 관여되어진다고 보고되고 있다. (중략)

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.409-415
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• 1985

This study has been carried out in order to investigate the bacterial quality of fish meat paste products and the characteristics of isolated thermodurics from the products. Twenty samples of crab-flavored fish stick (Kematsal), 23 samples of plate fish meat paste (Panomuk, Kamaboko), 5 samples of fried fish meat paste (Tigimomuk), 2 samples of roasted fish meat paste (Puduromuk, Chikuwa), 20 samples of fish sausage were collected from processing plants and supermarkets in Pusan, Korea during the period from May to October in 1984. The results obtained are as follows. Amont the samples collected from supermarkets, roasted fish meat paste and fried fish meat paste marked hish counts in coliforms and fungi while very low in the samples of crab-flavored fish stick and plate fish meat paste. Salmonella was not detected in all the samples examined and Staphylococcus aureus was detected only in fried fish meat paste, Thermoduric bacteria were detected less than 10$^2$/g in the samples of crab-flavored fish stick and plate fish meat paste, which might come from subsidiary materials such as starch and seasonings. Among the isolated bacteria, distribution of the proteolytics were more than 87％ and the lipolytics were less than 20％. Gram positive bacteria was more than 70％ in crab-flavored fish stick and plate fish meat paste, 47.3％ in fried fish meat paste. And rod in shape was almost more than 90％ in all the samples. The most heat resistant bacterium isolated from the samples was identified as a Bacillus licheniformis(named B. licheniformis CR-11). The strain showed strong proteolytic activity and also grew well at above 2$0^{\circ}C$. The growth rate and generation time of CR-11 strain were 0.31 hr$^{-1}$ , 2.24 hr at 2$0^{\circ}C$, 0.64 hr$^{-1}$ , 1.09 hr at 3$0^{\circ}C$ and 0.78 hr$^{-1}$ , 0.89 hr at 35$^{\circ}C$. Heat resistance value of the spores of CR-11 strain suspended in phosphate buffer solution was D$_{85}$ $^{\circ}C$=41.9 min, D$_{90}$ $^{\circ}C$=27.9 min, D$_{95}$ $^{\circ}C$=10.2 min, D$_{100}$ $^{\circ}C$=4.3 min (Z=13.8$^{\circ}C$)

• Journal of Life Science
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• v.30 no.3
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• pp.304-312
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• 2020

Agarase can be used in the field of basic science, as well as for production of agar-derived high-functional oligosaccharides and bioenergy production using algae. In 2012, we summarized the classification, origin, production, and applications of agar. In this paper, we briefly review the literature on the recombinant expression of agarases from 2012 to the present. Agarase genes originated from 19 genera, including Agarivorans, Flammeovirga, Pseudoalteromonas, Gayadomonas, Catenovulum, Microbulbifer, Cellulophaga, Saccharophagus, Simiduia, and Vibrio. Of the 47 recombinant agarases, there were only two α-agarases, while the rest were β-agarases. All α-agarases produced agarotetraose, while β-agarases yielded many neoagarooligosaccharides ranging from neoagarobiose to neoagarododecaose. The optimum temperature ranged between 25 and 60℃, and the optimum pH ranged from 3.0 to 8.5. There were 14 agarases with an optimum temperature of 50℃ or higher, where agar is in sol state after melting. Artificial mutations, including manipulation of carbohydrate-binding modules (CBM), increased thermostability and simultaneously raised the optimum temperature and activity. Many hosts and secretion signals or riboswitches have been used for recombinant expression. In addition to gene recombination based on the amino acid sequence after agarase purification, recombinant expression of the putative agarase genes after genome sequencing and metagenome-derived agarases have been studied. This study is expected to be actively used in the application fields of agarase and agarase itself.