• The Korean Journal of Ecology
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• 제26권2호
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• pp.82-86
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• 2003

We investigated the variation in adaptation to growth for four ecotypically-differentiated population of Taraxacum officinale found naturally in temporal environmental heterogeneity. Seeds collected from the four seasons were germinated in incubators and were grown for four months in greenhouse to test genetic variation among biotypes. Biotypes, segregated by seeds collected seasonally, were the part of natural population in Mokpo, South Korea. Each biotype was different in total dry weight of seeds, biomass, and leaf area, confirming previous finding. Differences between biotypes grown under a common environment indicated a genetic basis to their distinct demographic rates. Therefore, biotypes with similar annual rates of growth and contrasting seasonal rates should persist in the population. This differential response suggests that temporal variation in environment may be responsible, in part, for the maintenance of genetic variation within populations.

• 미생물학회지
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• 제24권1호
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• pp.51-56
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• 1986

Eight strains of the bacteria capable of growing on salicylate as the sole carbon source were isolated form soil and river water. Three of these isolates were identified as Acinetobacter calcoaceticus (AcBl), Pseuomonas putida biotype B (PpB2), and P. putida biotype A (PpB3). Effects of temperature, pH and C source concentration on biodegradation of salicylate by PpB3 were wxamined. The optimum conditions were as follows; $30^{\circ}C$ for temperature, 7.0 for pH, and 10mM for C source concentration. Ultraviolet scanning spectrum of the salicylate was measured. The spectrum has two peaks at 225nm and 292nm. The spectra of the culture filtrates indicate that ring degradation of salicylate is accomplished.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
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• pp.398-400
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• 2004

• 한국작물학회지
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• 제48권4호
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• pp.286-291
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• 2003

Monochoria vaginalis is one of the most troublesome resistant weeds in Korean rice culture. Thus, the objectives of this study were to evaluate the response of M. vaginalis resistant to sulfonylurea(SU) herbicides and to determine alternative herbicides for the control of resistant M. vaginalis in direct seeded and transplanted rice culture in Korea. In greenhouse studies, the resistant biotype was 31-, 38-, 3172-, and 7-fold more resistant to ben-sulfuron-methyl, cyclosulfamuron, imazosulfuron, and pyrazosulfuron-ethyl, respectively, than the susceptible biotype, indicating cross-resistance to the SU herbicides used in this study. Non-SU herbicides, butachlor, carfentrazone-ethyl, mefenacet, pretilachlor, pyrazolate, and thiobencarb, several SU herbicide-based mixtures, ethoxysulfuron plus fentrazamide, pyrazosulfuron-ethyl plus pyrazolate plus simetryn, and non-SU herbicide-based mixtures, pyrazolate plus butachlor, pyrazolate plus pretilachlor, simetryn plus molinate, carfentrazone-ethyl plus butachlor, and carfentrazone-ethyl plus thiobencarb can be used to control both the resistant and susceptible biotypes of M. vaginalis when applied before the second leaf stage. In the field experiment, the resistant biotype of M. vaginalis that survived from the paddy fields treated with a SU herbicide-based mixture could effectively be controlled by using mixtures of bentazone plus MCPA, bentazone plus mecoprop-P, and bentazone plus 2,4-D when applied at 2 or 4 main leaves. Our results suggest that the SU-resistant M. vaginalis had not developed multiple resistances to herbicides with different modes of action. In particular, bentazone plus MCPA and bentazone plus mecoprop-P were effective control measures after failure to control resistant M. vaginalis in Korean rice culture.

• 한국식품과학회지
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• 제33권4호
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• pp.486-491
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• 2001

국내외에서 분양 받고 국내식육에서 분리된 총 100균주의 Y. enterocolitica에 대한 병원성여부를 HEp-2세포 침투성 시험법을 기준으로 하고 여러 가지 병원성 확인 방법을 비교하였다. 혈청형만으로 병원성을 판단하기에는 충분하지 않았고 이외의 방법 즉, esculin과 salicin시험, pyrazinamidase 시험, biotype 등의 생화학적 특성에 바탕을 둔 실험 단독으로 병원성을 판단하기에는 완전하지 않았다. D-xylose 발효실험, CRMOX agar 시험과 자동응고반응(Autoagglutination)들은 병원성확인에 보조적인 역할만을 할 수 있었다. HEp-2 세포 침투성 시험법은 시간과 노력이 많이 소요되므로 이 방법을 대치할 수 있는 간단하고 신속, 정확하게 Y. enterocolitica 병원성을 확인할 수 있는 방법은 esculin시험에서 음성반응을 보이는 것만 PCR시험을 행하여 판별하는 것이라고 사려된다.

• 한국어병학회지
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• 제18권3호
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• pp.205-214
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• 2005

최근 2년간 동해안 지역 넙치 양식장의 양식 넙치에 피해를 일으키는 P. damselae 균을 분리하였으며, 분리된 P. damselae의 16s rRNA 염기 서열은 P. damselae subsp. damselae ATCC 33539와 99%의 상동성을 나타내었다. 분리 균주는 Pedersen et al.(1997)의 biotype과 비교한 결과, biotype No 8과 동일하게 나타났으며, P. damselae subsp. damselae ATCC 33539의 LPS와 동일한 단백질 패턴을 나타내었다. 넙치의 병어로부터 P. damselae와 Vibrio 속 세균의 감염 상태를 조사한 결과, P. damselae가 가장 높은 감염율을 나타내었고, 그 다음으로 V. anguillarum, V. splendidus, V. harveyi와 V. ordalii순으로 감염율이 나타났다.

• 한국동물위생학회지
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• 제21권4호
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• pp.451-465
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• 1998

The present study was carried out to investigate the prevalence of brucellosis in Kyungbuk area for the 3 years from 1966 to 1998. Collective milk samples were routinely screened to detect positive farms by using the milk ring test(MRT), and serum agglutination test was performed to detect sero-positive individuals in the MRT positive farms. Attempt were made to isolate the causative organismas from slaughtered sero-positive reactors and some biochemical and polymerase chain reation characters of the isolates were also made to identify the organisms. Seroprevalence to brucellosis in peoples who are close contact with infected dairy herds was also investigated. Brucellosis of dairy cattle was rare before 1997, but has been broken more frequently since early 1998. By the MRT for dairy herds, positive rate was gradually increased every year : 0.6% in 1996, 1.5% in 1997, 3.9% in 1998. Among 262 MRT-positive herds, only 21 herds(8.0%) showed positive brucellosis in serological test. The isolation rates of Brucella sp from tested materials were 51.2% in supramammary glands, 39.5% in milks, and 50.0% in pulmonary Iymphnode, respectively. Isolated strain and biotype were Brucella(B) arbortus biotype 1 in 26 heads, and were B suis biotype 1 in 2 heads. Isolated strain and vaccine strain were very similar in their colony morphology and staining. In drug susceptibility, isolated stains(B abortus) and vaccine strain(B abortus RB-51) were sensitive to ampicillin, gentamycin, kanamycin, neomycin, penicillin, streptomycin, and to tetracycline, but resistant to erythromycin. In the PCR, field strains reacted to BA and IS711 primers, and vaccine strain reacted to BA, IS711, and RB5l primers. In the plate agglutination test of 96 sera of human contacted with animals, serum antibody titer detected 1 : 100 in one person, 1 : 200 in one, and below 1 : 25 in the others.

• 대한미생물학회지
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• 제18권1호
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• pp.11-21
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• 1983

Various investigations have been carried out to elucidate the causative relationship between specific oral bacterial species and dental caries since it was first demonstrated that selected streptococoal species produced dental caries in germfree rats when fed a high-sucrose diet. Now, S. mutans is considered to play an important role in the development of dental caries in animals and humans, and only a limited number of species of bacteria other than S. mutans are occasionally found to be cariogenic in experimental animals. In this regard, association of the number of S. mutans in approximal plaque with caries experience (DMFT) was studied from 137 Korean school children($10{\sim}11$ year old). Biotypes of the collected strains of S. mutans were determined, and their relationship with caries status was also examined. The following results were emerged from the study. 1. S. mutans was detected in the plaques of all children. 2. Statistically significant positive correlation(r=0.445, p<0.001) was found between the caries experience(DMFT) and the number of S. mutans in approximal plaques. 3. The number of S. mutans were significantly higher(p<0.001) in plaques removed from carious surface than from sound surface. 4. The most frequent biotype was biotype I(78.8%), followed by IV(33.1%) and V(09.5%). Biotype II was isolated in the plaque of two children(1.7%) only. 5. There was no apparent relation of specific biotypes to carious status.

• 구강회복응용과학지
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• 제35권4호
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• pp.253-259
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• 2019

본 증례 보고는 하악 전치에 발생한 치은 퇴축을 laterally closed tunnel technique을 이용하여 처치하였다. 환자는 모두 과거 교정 치료 시 하악 전치의 경사도를 변화시켰으며 치주 적으로 얇은 생체형을 가지고 있었다. 터널링법으로 수여 부를 형성하고 구개 측에서 채득한 결합조직이식편을 터널내에 위치시킨 후 판막의 변연을 치근 중앙부를 향해 측방으로 이동시켜 봉합하여 이식편을 피개 하였다. 얇은 치주 생체형에도 불구하고 치근 피개를 성공적으로 얻을 수 있었으며 각화 치은의 획득과 주변 조직과의 색, 형태 조화로 심미성을 달성할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.958-963
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• 2008

A series of experiments were conducted to assess the effectiveness of rhizobacteria containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase for growth promotion of peas under drought conditions. Ten rhizobacteria isolated from the rhizosphere of different crops (peas, wheat, and maize) were screened for their growth promoting ability in peas under axenic condition. Three rhizobacterial isolates, Pseudomonas fluorescens biotype G (ACC-5), P. fluorescens (ACC-14), and P. putida biotype A (Q-7), were selected for pot trial on the basis of their source, ACC deaminase activity, root colonization, and growth promoting activity under axenic conditions. Inoculated and uninoculated (control) seeds of pea cultivar 2000 were sown in pots (4 seeds/pot) at different soil moisture levels (25, 50, 75, and 100% of field capacity). Results revealed that decreasing the soil moisture levels from 100 to 25% of field capacity significantly decreased the growth of peas. However, inoculation of peas with rhizobacteria containing ACC deaminase significantly decreased the "drought stress imposed effects" on growth of peas, although with variable efficacy at different moisture levels. At the lowest soil moisture level (25% field capacity), rhizobacterial isolate Pseudomonas fluorescens biotype G (ACC-5) was found to be more promising compared with the other isolates, as it caused maximum increases in fresh weight, dry weight, root length, shoot length, number of leaves per plant, and water use efficiency on fresh and dry weight basis (45, 150, 92, 45, 140, 46, and 147%, respectively) compared with respective uninoculated controls. It is highly likely that rhizobacteria containing ACC deaminase might have decreased the drought-stress induced ethylene in inoculated plants, which resulted in better growth of plants even at low moisture levels. Therefore, inoculation with rhizobacteria containing ACC deaminase could be helpful in eliminating the inhibitory effects of drought stress on the growth of peas.