• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.327-332
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• 1994

Optimum conditions for the production of acetoin and ammonia as the precursors of tetramethylpyrazine(TMP) were determined using Lactococcus lactis subsp. lactis biovar. diacetylactis FC1 in a modified Lactose-citrate broth containing galactose, citrate, and arginine. The cell growth and the productivity of acetoin and ammonia were remarkably increased in an aerobic culture with 10 $\mu M$ of hematin. For the optimum conditions of acetoin and ammonia production, the concentration of citrate and arginine were adjusted to 156 mM and 50 mM after 18 hr cultivation, and citrate and galactose to 156 mM and 50 mM after 36 hr cultivation, respectively. In these conditions, acetoin and ammonia were produced to the final concentration of 127 mM and 195 mM, which were the highest concentations, respectively. The optimum conditions of the TMP production were also determined as follows; 4 hours at 121, pH 8.3, and the maximal yield of TMP under these conditions was 0.81 g/l.

• 식물병연구
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• 제22권4호
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• pp.276-283
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• 2016

2013년부터 2016년까지 P. syringae pv. actinidiae에 의한 궤양병에 감염된 것으로 확인된 과수원수는 202개였는데, Psa2가 73개 과수원에서 검출되었고 Psa3는 129개 과수원에서 검출되었다. 2015년에 비해 2016년 Psa2에 감염된 과수원은 거의 증가하지 않았지만 Psa3에 감염된 과수원은 두 배 가량 증가했다. 우리나라에서 재배하고 있는 키위 품종들 중에서 일부 토종다래를 제외한 모든 키위 품종들에서 Psa3가 검출되어 아직까지 Psa3에 저항성인 품종은 없다는 것이 확인되었다. 조사된 품종들 중에서 골드키위 품종인 Hort16A와 제시골드와 레드키위 품종인 홍양이 Psa3에 가장 감수성이었다. 경남지역에서 역학조사와 RAPD 분석 결과 2014년 홍양 과수원에서 최초 Psa3에 의한 궤양병은 중국에서 수입한 Psa3에 오염된 꽃가루에 의해 발생했고, 2016년 경남 사천과 고성 지역의 과수원들에서 궤양병의 대발생은 홍양 과수원으로부터 근처 제시골드와 헤이워드 과수원으로 2차감염에 의한 Psa3의 급속한 확산 때문으로 추정된다.

• Journal of Microbiology and Biotechnology
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• 제1권4호
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• pp.285-287
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• 1991

To produce the tetramethylpyrazine (TMP) flavor compound, Lactococcuss lactis subsp. lactis biovar. diacetilactis (L. diacetilactis) FC1 was cultivated in the TMP medium containing 3% (w/v) of Na-citrate and 6% (w/v) arginine-HC1 as substrates of acetoin and $NH_3$, respectively, which are the two precursors of the TMP. After 19-day fermentation at $34^{\circ}C$, 0.57 g/l or 4.19 mmole/l of the TMP was produced. This was the first result showing that the TMP could be produced by L. diacetilactis.

• 식물병연구
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• 제17권3호
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• pp.326-333
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• 2011

Ralstonia solanacearum에 의해 발생하는 토마토 풋마름병에 대하여 저항성으로 알려진 토마토 순계 품종의 국내 병원균에 대한 저항성 반응을 온도별로 평가하였다. 한국에서 분리된 R. solanacearum 균주로 토마토 순계 6 품종의 저항성을 평가한 결과 기존에 저항성으로 알려진 토마토 순계들이 한국 분리균주에 대하여는 대부분 저항성을 유지하지 못하였다. 병원성이 강한 균주인 SL341 (race 1, biovar 4) 균주는 검정한 대부분의 품종에서 온도에 관계없이 강한 병원성을 보였다. 반면, 담배에서 분리된 균주인 SL1944(race 1, biovar 4)은 온도에 따라 발병진전이 현저하게 차이가 났다. Moneymaker와 Bonny Best와 같은 품종은 온도에 관계없이 SL1944에 대하여 감수성이었다. 그러나, 풋마름병 저항성 품종으로 알려진 Hawaii 7998, Hawaii 7996, B-blocking 품종은 오히려 상대적으로 고온인 조건($35^{\circ}C$에서 14시간 명조건과 $28^{\circ}C$에서 10시간 암조건)에서 급격히 발병하였다. 병 진전은 동일한 품종의 낮은 온도에서 병 진전이나 Moneymaker나 Bonny Best 같은 품종에서 동일한 고온 조건의 발병에 비해 눈에 띄게 빨랐다. 본 연구결과는 국내에서 분리된 균주들이 기존에 저항성 토마토 품종을 가해할 수 있으며 고온조건에서는 품종의 저항성 붕괴의 가능성으로 급격한 풋마름병이 유발될 수 있음을 제시한다.

• The Plant Pathology Journal
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• 제33권4호
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• pp.351-361
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• 2017

Bacterial canker is the largest limiting factor in the cultivation and production of kiwifruit worldwide. Typical symptoms comprise necrotic spots on leaves, canker and dieback on canes and trunks, twig wilting, and blossom necrosis. Pseudomonas syringae pv. actinidiae (Psa), which is the causal agent of kiwifruit bacterial canker, is divided into four biovars based on multilocus sequence analysis of different genes, additional PCR testing of pathogenic genes (argKtox cluster, cfl, and various effector genes), and biochemical and physiological characterization. Bacterial canker caused by Psa biovar 2 designated Psa2 was detected for the first time on the green-fleshed kiwifruit cultivar Hayward in 1988 and the yellow-fleshed kiwifruit cultivar Hort16A in 2006 in Korea. Psa biovar 3 designated Psa3, responsible for the current global pandemics of kiwifruit bacterial canker, began to appear in Korea in 2011 and caused tremendous economic losses by destroying many vines or orchards of yellow-fleshed kiwifruit cultivars in one or several growing seasons. Bacterial canker epidemics caused by both Psa2 and Psa3 are prevalent in Korea in recent years. In this review, we summarize the symptomatology, etiology, disease cycle, diagnosis, and epidemiology of kiwifruit bacterial canker in Korea.

• 식물병연구
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• 제10권1호
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• pp.58-62
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• 2004

충북지역 토마토 시설재배지 토양의 풋마름병 병원균(Ralstonia solanaceaum)의 오염도 및 분리균의 특성을 조사하였다. 총 133개 조사 토양 중 27개 토양에서 선택배지로부터 R. solanacearum이 분리되어, 전체 시설재배지 토양의 20.3%가 풋마름병균에 오염되어 있음을 나타냈다. 오염 토양에서 병원균의 밀도는 토양 g당 $10^{2.4}$ cfu로 조사되었다. 병든 토마토로부터 분리한 12균주를 포함한 총 71개의 분리균주는 모두 레이스 1이었고, 35개 균주가 생리형 3으로, 36개 균주가 생리형 4로 구분되었다. 전체 분리균의 88% 이상이 각각 oxolinic acid 0.5$\mu\textrm{g}$/ml, streptomycin 25 $\mu\textrm{g}$/ml, tetracycline 5 $\mu\textrm{g}$/ml and cupric sulfate 375 $\mu\textrm{g}$ml(1.5 mM)을 함유한 nutrient agar에서 생장이 억제되었고, 전체균주의 11.3%, 4.2% and 5.6%가 각각 감수성균주의 최소억제농도보다 10배 이상의 oxolinic acid, streptomycin, tetracycline가 함유된 배지에서 생장하였다. 5개 균주는 2개의 살세균제에 동시에 그리고 1개 균주는 3개의 살세균제 모두에 저항성을 보였다.

• 미생물학회지
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• 제35권3호
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• pp.185-191
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• 1999

본 연구는 1997년 1월부터 1997년 11월까지 낙동강 기수지역인 다대포의 모래에서 서식하는 식용 쌍패각 조개인, 빛조개로부터 비브리오를 분리 동정한 것이다. 표현형을 중심으로 한 새와학적 성상으로 빛조개의 내장으로부터 Vibrio alginolyticus, V. parahaemolyticus, V. cholerae non-O1, V. vulnificus, V. salmonicida 및 V. tubiashii 등 8종의 비브리오가 동정되었다. 수온이 $15^{\circ}C$ 이하에서 성장이 불가능한 병원성 세균인 V.parahaemolyticus 가 동절기에 및조개로부터 분리됨으로서 빛조개가 자연계내에서 V.parahaemolyticus 의 월동 보균체중의 하나라는 결론을 얻게 되었다.

• Clinical and Experimental Pediatrics
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• 제53권12호
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• pp.989-993
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• 2010

Although numerous clinical observational studies have been conducted over a period of over 30 years, the clinical significance of $Ureaplasma$ infection is still under debate. The $Ureaplasma$ speices. is a commensal in the female genital tract and considered to have of low virulence; however, $Ureaplasma$ colonization has been associated with infertility, stillbirth, preterm delivery, histologic chorioamnionitis, and neonatal morbidities, including congenital pneumonia, meningitis, bronchopulmonary dysplasia, and perinatal death. Recently, $Ureaplasma$ was subdivided into 2 separate species and 14 serovars. $Ureaplasma$ $parvum$ is known as biovar 1 and contains serovars 1, 3, 6, and 14, and $Ureaplasma$ $urealyticum$ (biovar 2) contains the remaining serovars (2, 4, 5, and 7-13). The existence of differences in pathogenicities of these 14 serovars and 2 biovars is controversial. Although macrolides are the only antimicrobial agents currently available for use in neonatal ureaplasmal infections, in the current clinical field, it is difficult to make decisions regarding which antibiotics should be used. Future investigations involving large, multicenter, randomized, controlled studies are needed before proper recommendations can be made for clinical practice.

• 한국식물병리학회지
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• 제10권1호
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• pp.39-46
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• 1994

Pseudomonas fluorescens Biovar III strains S-2 antagonistic to Rhizoctonia solani was subjected to Tn5 mutagenesis by the transposon vector pGS9. Ampicillin and kanamycin resistant (Ampr, Kmr) transconjugants were recovered at a frequency of 1.3$\times$10-7 per initial recipient cell, when recipient cells were washed twice in TE buffer before conjugation. Of the ca. 3000 transconjugants, a frequency of noninhibitory (Inh-), nonfluorescent (Flu-) and auxotorphic (Pro-) mutants were 0.27%, 0.47% and 0.40%, respectively. In these mutants, all Inh- mutants showed the same colony morphology as wild type, whereas all Flu- and Pro- mutants inhibited the growth of R. solani. These mutants were also susceptible to chloramphenicol, indicating only the Tn5 element, except for parts of pGS9, was integrated into the recipient genome. In a Southern blot analysis, the Tn5 element inserted into one site on the chromosome for each of the chosen mutants. However, Tn5 insertion sites of Inh-, and Pro- mutants were differed in each other. These indicate that the genes essential for R. solani inhibition, fluorescent production and auxotrophic are chromosomally located, but not linked to each other.

• The Plant Pathology Journal
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• 제32권6호
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• pp.545-551
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• 2016

A bacterial pathogen, Pseudomonas syringae pv. actinidiae (Psa), is a causal agent of kiwifruit bacterial canker worldwide. Psa biovar 3 (Psa3) was first detected in 2011 at an orchard in Dodeok-myeon, Goheung-gun, Jeonnam Province in Korea. In this study, we present the results of an epidemiological study regarding Psa3 occurrence on kiwifruit orchards in Korea for the period of 2013 to 2015. Since the first detection of Psa3 in 2011, there was no further case reported by 2013. However, Psa3 was rapidly spreading to 33 orchards in 2014; except for three orchards in Sacheon-si, Gyeongnam Province, most cases were reported in Jeju Island. Entering 2015, bacterial canker by Psa3 became a pandemic in Korea, spreading to 72 orchards in Jeju Island, Jeonnam, and Gyeongnam Provinces. Our epidemiological study indicated that the first Psa3 incidence in 2011 might result from an introduction of Psa3 through imported seedlings from China in 2006. Apart from this, it was estimated that most Psa3 outbreaks from 2014 to 2015 were caused by pollens imported from New Zealand and China for artificial pollination. Most kiwifruit cultivars growing in Korea were infected with Psa3; yellow-fleshed cultivars (Yellow-king, Hort16A, Enza-gold, Zecy-gold, and Haegeum), red-fleshed cultivars (Hongyang and Enza-Red), green-fleshed cultivars (Hayward and Daeheung), and even a kiwiberry (Skinny-green). However, susceptibility to canker differed among cultivars; yellow- and red-fleshed cultivars showed much more severe symptoms compared to the green-fleshed cultivars of kiwifruit and a kiwiberry.