• 미생물학회지
• /
• 제48권4호
• /
• pp.325-327
• /
• 2012

먹물버섯 C. congregatus의 자가분해되는 자실체 조직에서 발현되는 chitinase (Chi2)가 식물병원성 균류인 A. alternata와 F. graminearum를 대상으로 고체배지와 액체배지에서 포자의 발아 및 균사 생장에 대하여 보이는 억제효과 실험을 수행하였다. 액체배지에서 $50{\mu}g/ml$의 Chi2 농도에서 A. alternata의 포자 발아가 90% 이상 억제되었고, $70{\mu}g/ml$의 농도에서 실험균류 모두 생장이 억제되었다. 고체배지에서 하루에 $6{\mu}g$씩 2회 더한 Chi2에 의하여 F. graminearum 균사 생장이 억제됨을 확인하였고, 이때 균사의 branching이 상대적으로 감소하였다.

• 한국생물물리학회:학술대회논문집
• /
• 한국생물물리학회 2003년도 정기총회 및 학술발표회
• /
• pp.61-61
• /
• 2003

We have cloned the CGR1 gene encoding glutathione reductase (GR) which catalyzes the reduction of oxidized glutathione (GSSG) to reduced glutathione (GSH) from Candida albicans. The cgr1/cgr1 mutants were not viable when CaMAL2 promoter repressed the CGR1 expression. The growth of the mutants could be partially overcome by thiol compounds such as GSH, dithiothreitol, cysteine, N-acetylcysteine and GSSG. Interestingly, C. albicans with CGR1 overexpressed showed defective hyphal growth on solid medium and attenuated virulence. We have also cloned the GCS1 gene encoding ${\gamma}$-glutamylcysteine synthetase which catalyzes the first step of glutathione biosynthesis. The gcs1/gcs1 mutants were nonviable in minimal defined medium. The growth of the mutants could be resumed by supplementing with GSH, GSSG and ${\gamma}$-glutamylcysteine in the medium. The mutants had increased intracellular D-erythroascorbic acid level up to 2.25-fold when transferred to GSH-free medium. When the mutants were depleted of GSH, they showed typical markers of apoptosis. In conclusion, these results suggest that glutathione is an essential metabolite, and involved in hyphal growth, virulence and apoptosis in C. albicans.

• 한국응용곤충학회지
• /
• 제26권1호
• /
• pp.43-47
• /
• 1987

도열병병반형성(稻熱病病斑形成)에 미치는 침입률(侵入率)과 균사신전도(菌絲伸展度)의 효과(效果)를 알기 위(爲)하여 23/15C(주/야(晝/夜)), 29/21C 및 온실조건(溫室條件)($33{\sim}23C$)에서 처리(處理)한 Aichi-asahi, Toyotama, Yamabiko에 6개의 도열병균(稻熱病菌) 균주(菌株)를 접종(接種)한 결과(結果), 접종후(接種後) 72,96시간(時間)째의 침입률(侵入率)은 어느 온도조건(溫度條件)에서도 병반형성(病斑形成)과 고도(高度)의 유의성(有意性)이 있었다. 또한 균사신전도(菌絲伸展度) 11이상(以上)을 나타내는 부착기수(付着器數)도 병반수(病斑數)와 고도(高度)의 유의성(有意性)이 인정(認定)되었다. 그러나 균사신전도(菌絲伸展度) 30이상(以上)을 나타내는 부착기수(付着器數)는 29/21C조건(條件)의 접종후(接種後) 72시간(時間)째에만 유의성(有意性)이 인정(認定)되었다. 이들 상관관계(相關關係)의 통계적(統計的)인 적중도(的中度)는 29/21C나 온실(溫室)보다는 23/15C에서 더 높았으며 이런 현상(現象)은 이병성품종(罹病性品種)인 Aichi-asahi에서 더욱 뚜렷하였다.

• 약학회지
• /
• 제55권3호
• /
• pp.234-239
• /
• 2011

Glycycoumarin, a 3-arylcoumarine isolated from Glycyrrhizae radix (a family of Leguminosae), is reported to have anti-bacterial activity. However, its antifungal activity is still unknown. In this present study, the antifungal activity of glycycoumarin (GLM) against Candida albicans, a polymorphic fungus was investigated. Possible mechanism such as blocking of the hyphal induction was also analyzed. By the in-vitro susceptibility analysis, GLM showed anticandidal activity, resulting in an almost complete inhibition of the fungal growth at a concentration of 320 ${\mu}g/ml$, which was equivalent to the efficacy of fluconazole at the same dose. In the murine model of disseminated candidiasis GLM enhanced resistance of mice against the disseminated disease (P<0.05), resulting in 60% protection of GLM-treated mice group during a period of 21-day observation. As for its mechanism of the antifungal activity, GLM blocked hyphal production, one of the important of virulence factors by the fungus, from the yeast form of C. albicans (P<0.01). These data indicate that GLM may contribute to the perspectives that focus on the development of a novel agent with antifungal activity specific for C. albicans infection.

• 약학회지
• /
• 제57권6호
• /
• pp.383-387
• /
• 2013

In the present study, we determined the antifungal effect of obacunone isolated from Phellodendri Cortex against Candida ablicans, a pathogenic fungus. The antifungal effect was analyzed by an in-vitro susceptibility test and in a murine model of disseminated candidiasis. Possible mechanism of the antifungal activity was also examined. Analyses of data resulting from the susceptibility test revealed that the compound inhibited C. albicans growth. At 25 ${\mu}g$ obacunone/ml, there was app. 45% reduction of CFUs (colony forming units) as compared to obacunone-untreated C. albicans yeast cells (P<0.01). In the murine model of disseminated candidiasis due to C. albicans, obacunone enhanced resistance of mice against disseminated candidiasis. During an entire period of 30-day observation, control animals all died within 14 days, whereas 60% of obacunone-treated mice survived (P<0.05). In addition, obacunone inhibited the hyphal production, a major virulence factor of C. albicans, from the blastoconidial form. Thus, obacunone appears to have antifungal activity for C. albicans infection. This may possibly be mediated by the blockage of hyphal production.

• 한국환경농학회지
• /
• 제23권4호
• /
• pp.191-196
• /
• 2004

The contribution of plant nutrition status in arbuscular mycorrhizal (AM) plant to the nutrient acquisition by extraradical hyphae of AM fungi was investigated using cucumber colonized with Glomus intraradicies (BEG 110) focusing on the Zn. Compartmentalized pots with separated Bones for hyphal growth were used to determine the contribution of extraradical AM hyphae to Zn uptake from hyphal zones. $0.5\;{\mu}M$ Zn was supplied into the hyphal zones as nutrient solution (10 mL/day) with a form of $ZnSO_4$. Zn foliar application was made two times for one week before harvest (8 mL/plant). The colonization rate by AM were high in all of Zn treatments. The dry weight of cucumber increased by AM colonization compared to those of non-mycorrhizal counterpart. However: Zn foliar application resulted in no significant difference in dry weight between mycorrhizal- and non-mycorrhizal plant. In addition, the enhancement of Zn content in cucumber shoot by AM colonization were also reduced by Zn foliar application. These results indicate that the interaction between host plant and AM fungus for nutrient uptake might be related to plant nutritional status and nutrient contents. In consequence, higher Zn contents in host plant by foliar application of Zn could restrict the role of extraradical hyphae of AM fungus on the Zn acquisition and transfer from fungus to host plant.

• 한국식물병리학회지
• /
• 제1권1호
• /
• pp.72-78
• /
• 1985

무 포장에서 분리한 Rhizoctonia solani 5군 4형의 7균주(AG1-IA, AG1-IB, AG2-1, AG2-2, AG3, AG4, AG5)를 사용하여 온도, pH, 질소원, 탄소원이 균의 생장에 미치는 영향을 알아보았다. 이들 균사융합군주별, 최적생장온도는 AG2-1, AG2-2, AG4 등은 $20^{\circ}C$에서 AG1-IA, AG1-IB, AG3, AG5 등은 $25^{\circ}C$에서 생장이 가장 양호하였다. pH가 균사융합군별 생장에 미치는 영향은 공히 pH $6\~7$ 범위였다. R. solani의 각 균주별 탄소원 이용도는 AG 1-IA, AG1-IB, AG2-2, AG3, AG5는 glucose, AG2-1은 sucrose, AG4는 fructose가 좋았으나, glycerine, cellulose, lactose는 모든 균주에서 생장이 불량하였다. 질소원이 균사융합군별 각 균주의 생장에 미치는 영향은 $Ca(NO_3)_2$에서 AG1-IA, AG1-IB, AG4, asparagine에서는 AG2-1, $KNO_3$에서는 AG2-2, $NaNO_3$에서는 AG5의 생장이 양호하였으나, $NH_4NO_3$ 첨가구에서는 공히 불량하였다. 즉, 일반적으로 초산태질소와 유기질소는 암모니아태질소보다 이용율이 높았다. C/N율이 각 군별 균주의 생장에 미치는 영향은 C:N=1:1의 비율에서 생장이 가장 좋았고 탄소원보다는 질소원이 생장에 많은 영향을 미쳤다.

• The Plant Pathology Journal
• /
• 제29권1호
• /
• pp.42-51
• /
• 2013

One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus.

• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 2009년도 International Meeting of the Microbiological Society of Korea
• /
• pp.86-87
• /
• 2009

• 한국균학회지
• /
• 제30권2호
• /
• pp.157-165
• /
• 2002

국내 35개 골프장에 식재된 잔디류의 잎마름 증상으로부터 분리한 125개 Pythium spp. 균주 중 분리시기별, 골프장별 그리고 Pythium spp. 별로 선발한 44개 균주를 사용하여 실내실험을 통해 metalaxyl에 대한 감수성정도를 조사하였다. 다양한 농도(0, 0.1, 1.0, 10.0, 50.0, 100.0 및 $250.0{\mu}g\;a.\;i./ml$)로 metalaxyl을 함유한 Difco corn meal agar 배지에서 균사생장억제 정도를 조사한 결과 1.0과 $10.0{\mu}g\;a.\;i./ml$수준의 metalaxyl에 대해 감수성정도에 따라 크게 2 group으로 나눌 수 있었다. Metalaxyl 함량이 $10.0{\mu}g\;a.\;i./ml$에서 균사생장억제율은 감수성 group에 속한 31개 균쥬는 $66{\sim}98%$, 저항성 group에 속한 13개 균주는 $6{\sim}26%$이었고. $10.0{\mu}g\;a.\;i./ml$에서는 각각 $82{\sim}99%$와 $27{\sim}47%$를 나타냈다. 이처럼 metalaxyl에 저항성을 나타내는 Pythium spp.의 출현과 골프장 잔디에서의 분리는 국내에서 처음 보고되는 것이다. Metalaxyl에 저항성을 나타낸 Pythium spp. 균주 중 분리빈도가 상대적으로 높았던 P. graminicola 중 metalaxyl에 감수성을 나타내는 4개 균주와 저항성을 나타내는 3개 균주를 이용하여 pot 내 creeping bentgrass에 대하여 농약 스크리닝시험을 한 결과 metalaxyl 감수성 균의 경우 $6.25{\mu}g\;a.\;i./ml$ 처리구에서는 병 발생이 없었지만 저항성 균의 경우는 $12.5{\mu}g\;a.\;i/ml$와 그 이상의 처리구에서도 방제가 되지 않았다. 50.0과 $100.0{\mu}g\;a.\;i/ml$ 처리구에서는 creeping bentgrass에 약해를 나타냈다. 병원균 접종 전 약제처리가 발병 후 처리에 비하여 우수한 방제효과를 나타냈다.