Genome-wide screening antifungal genes in <i>Streptomyces griseus</i> S4-7, a Fusarium wilt disease suppressive microbial agent

Hong, Sung Won,Kim, Da-Ran,Kwon, Youn Sang,Kwak, Youn-Sig Published by Elsevier/North Holland on behalf of t 2019 FEMS microbiology letters Vol.366 No.12

<P> <I>Streptomyces</I> is a widely studied bacterial genus, particularly with regard to secondary metabolites and antibiotics production. <I>Streptomyces griseus</I> S4-7 was isolated from a strawberry Fusarium wilt disease suppressive soil, and its biological control ability has been well established. However, the antifungal mechanism of strain S4-7 is not yet fully understood at the molecular and biochemical level. Therefore, in this study we created a random mutant library for strain S4-7 with the Tn5 transposon element to investigate antifungal traits on a genome-wide scale. In total 4646 individual mutant strains were created and 13 mutants were selected based on loss of antifungal activity. The knockout genes were identified as electron transfer oxidoreductase (eto),sigma factor-70(sig70) and nrps by Inverse PCR (I-PCR). eto regulates the <I>geranylgeranyl</I> reductase gene, which is involved in terpenoid-quinone biosynthesis, an important factor in cell fitness. In the <I>△eto</I> strain, expression of <I>wbl,</I> a master regulator of the production of secondary metabolites, was significantly reduced. sig70 is responsible for the cell differentiation sensing mechanism in genus <I>Streptomyces. △nrps</I> showed decreased production of hybrid peptide-polyketide siderophores. These results suggest that <I>S. griseus</I> S4-7 may have various antifungal mechanisms, and each mechanism is essential to maximal antifungal activity. <P>

신경회로망을 이용한 용접잔류응력 예측 및 최적의 용접조건 선정에 관한 연구

차용훈,김하식,이연신,김덕중,성백섭 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.1

The objective of the study is the development of the system for effective prediction of residual stresses using the back propagation algorithm from the neural network. The achieve of this goal, the series experiment were carried out and measured the residual stresses using sectional method. Using the experimental results, the optional control algorithms using a neural network should be developed in order to reduce than the effect of the external distribution during GMA welding processes. Also, comparison with the measured and the calculated results from the FEM(finite element method) and verification of the developed system was carried out. This system can not only help to understand the interaction between the process parameters and residual stress, but also, improve the quantity control for welded structures. Then the results obtained from this study are as follows. Through comparison between the measured and calculated results, the neural network based on back propagation algorithm is the best techniques to predict the process parameter. A new techniques which predict the process parameter such as welding voltage, arc current, welding speed using the training the raw dates, will be proposed.

신경회로망을 이용한 용접잔류응력 예측에 관한 연구

차용훈,김일수,김하식,이연신,김덕중,성백섭,서준열 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.6

In order to achieve effective prediction of residual stresses, the series experiment were carried out and the residual stress-es were measured using the backpropagation algorithm from the neural network and the sectional method. Using the experimental results, the optiomal control algorithms using a neural network should be developed in order to reduce the effect of the external disturbances on residual stresses during GMA welding processes. The results obtained from the comparison between the measured and calculated results, showed that the neural network based on backpropagation algorithm can be used in order to control weld quality. This system can not only help to under-stand the interaction between the process parameters and residual stress, but also, improve the quantity control for welded structures. The development of the system is goal in this study.

Crop Health Management through understanding Microbiota Community Ecology

Youn-Sig Kwak(곽연식) 한국농약과학회 2022 한국농약과학회 학술발표대회 논문집 Vol.2022 No.11

Plants lack genetic resistance to most necrotrophic pathogens. To compensate for this disadvantage, plants recruit antagonistic members of microbiota to defend themselves against pathogens and other pests. Pseudomonas, Bacillus, and Trichoderma are well-known plant probiotic agents, which can protect plants against various biotic and abiotic stresses. In 2015, the Phytobiome initiative was launched by the White House. Phytobiomes consist of crops, the environment, and associated communities of microbes. Interkingdom interaction within the microbiome is dynamic and critical affecting crops and agroecosystem healthiness. In this presentation, a new probiotic strain Streptomyces, plant and environment factorial interaction, and the impact of the microbe in the agroecosystem will be introduced. Streptomyces is a gram-positive bacterium and more than two third of antibiotic compounds, currently used in the human clinic, are originated from the bacterium. However, in interaction with plant and agrosystem, the role and weight of Streptomyces is undervalued. Therefore, we recently start “STreptomyce in Agriculture Research” project with various cropping systems. Of special interest is that rhizosphere and anthosphere microbial community structures and shifting have been analyzed using massive pyrosequencing platforms. Based on the results, three putative probiotic Streptomyces strains have been isolated and characterized. The strains were well colonized in the rhizosphere, anthosphere, and phyllosphere. Unexpectedly, the three independent stains were revealed they had identical genome sequences. The following questions arise why the identical stains exist in totally different habitats and what is the function of the strains in such a system? In conclusion, Streptomyces is ubiquitous and unique in the system to provide a beneficial effect to both plant and it phytobiome communities. The STAR project will provide more opportunities and possibilities in agriculture.

Tracking Center Frequency of Seaway Signal Using A New Master-Slave Filter Bank

Hyong Sig Youn,Jae Whan Lim,Jae Seung Choi,Sang Hui Park 대한전자공학회 1994 대한전자공학회 Proceedings Vol.1994 No.-

적응노치필터를 이용한 심도제어시스템 외란처리

김윤호(Youn-ho Kim),윤형식(Hyong-Sig Youn),임재환(Jae-Whoan Lim),이석필(Suk-pi1 Lee),박상희(사회자) 제어로봇시스템학회 1992 제어로봇시스템학회 국내학술대회 논문집 Vol.1 No.1

Improved Parallel Spatial Processing for Suppression of Coherent Jamming Signals

Won Sig Youn 대한전자공학회 1991 KITE JOURNAL OF ELECTRONICS ENGINEERING Vol.2 No.1

Different oxidative burst patterns occur during host and nonhost resistance responses triggered by Xanthomonas campestris in pepper

Kwak, Youn-Sig,Han, Ki-Soo,Lee, Jung-Han,Lee, Kyung-Hee,Chung, Woo-Sik,Mysore, Kirankumar S.,Kwon, Young-Sang,Kim, Hee-Kyu,Bae, Dong-Won The Korean Society of Plant Biotechnology 2009 식물생명공학회지 Vol.36 No.3

The hypersensitive reaction (HR) is the most common plant defense reaction against pathogens. HR is produced during both host- and nonhost-incompatible interactions. Several reports suggest that similarities exist between host and nonhost resistances. We assayed the pattern of generation of reactive oxygen species (ROS) and scavenging enzyme activities during nonhost pathogen-plant interactions (Xanthomonas campestris pv. campestris/Capsicum annuum L.) and incompatible host pathogen-plant interactions (Xanthomonas campestris pv. vesicatoria race1/Capsicum annuum L.). Both ${O_2}^-\;and\;H_2O_2 $ accumulated much faster during nonhost resistance when compared to the host resistance. The scavenging enzyme activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) were also different during the host- and nonhost-incompatible interactions. CAT activity was much higher during nonhost resistance, and several new isozymes of SOD and POX were detected during nonhost resistance when compared to the host resistance. Lipoxygenase (LOX) activity was higher in host resistance than nonhost resistance during the early stages of infection. Interestingly, the nitric oxide (NO) radical accumulated equal amounts during both host and nonhost resistance at early stages of infection. Further studies are needed to determine the specific pathways underlying these differences between host and nonhost resistance responses.

적응노치필터를 이용한 심도제어시스템 외란처리

김윤호(Youn-ho Kim),윤형식(Hyong-Sig Youn),임재환(Jae-Whoan Lim),이석필(Suk-pil Lee),박상희(Sang-Hui Park) 대한전자공학회 1992 대한전자공학회 학술대회 Vol.1992 No.10

One of the most difficult problems in depth control for underwater vehicle is the effect of seaway disturbance. One component of the seaway forces is of large magnitude with a relatively narrow-band, first order component. The other component is generally of somewhat smaller magnitude, second order component. Since the magnitude of the first order component is generally much greater than the compensating force that can be generating by the planes, it is undesirable for the controller to generate a control command. In this paper, we designed adaptive notch filtering system using filter bank structure. Energies of each band-passed signal are obtained by MA(Moving Average )method and compared to produce center frequency. By adapting this parameter to notch filter, lst order seaway disturbance can be removed, which lead to the improvement of automatic depth control system.

미생물 군집의 이해를 통한 유기농업 작물 건강관리

곽연식 ( Youn-sig Kwak ) 한국환경농학회 2023 한국환경농학회 학술대회집 Vol.2023 No.0

식물은 대부분의 괴사성 병원체에 대해 유전적 저항력을 갖지 못한다. 이를 보완하기 위해, 식물은 미생물 군집에서 유익한 미생물을 동원하여 병원체와 해충으로부터 자신을 방어한다. Pseudomonas, Bacillus, 그리고 Trichoderma는 식물을 다양한 스트레스로부터 보호하는 잘 알려진 식물 프로바이오틱스이다. 2015년 식물마이크로바이옴 이니셔티브는 작물 건강과 생태계 균형에서 식물-미생물 군집의 중요성이 강조되었다. 본 발표에서는 Streptomyces라는 새로운 프로바이오틱스 균주, 식물 및 환경과의 상호작용, 그리고 농업 생태계에 미치는 영향을 소개하고자 한다. 인간이 사용하는 항생물질의 70% 이상이 Streptomyces에서 유래되었다. 그러나 Streptomyces의 식물 및 농업 생태계 상호작용에서의 역할과 중요성은 심도 있는 접근이 이루어지지 않았다. 이를 해결하기 위해 우리는 “농업 연구에서의 Streptomyces (STAR)” 프로젝트를 시작하였다. 이 프로젝트는 다양한 작물 재배 체계에 초점을 맞추었다. 차세대 파이로시퀀싱 플랫폼을 사용하여 작물의 근권, 꽃권, 그리고 내권의 미생물 군집을 분석하였다. 연구를 통해 식물의 뿌리, 꽃, 그리고 내부조직에서 서식하는 세 가지의 가상 프로바이오틱스 Streptomyces 균주를 분리 및 특성화했다. 놀랍게도, 이 세 균주는 서로 다른 서식지에서 발견되었음에도 동일한 유전체 서열을 보였다. 이는 서로 다른 시스템에서 동일한 균주의 존재와 기능에 관한 의문을 제기하였다. 결론적으로, Streptomyces는 작물 생태계에 유익한 효과를 제공하는 널리 분포하는 독특한 미생물이다. STAR 프로젝트는 유기농 농업을 위한 유망한 기회와 가능성을 가지고 있다. Plants lack genetic resistance to most necrotrophic pathogens. To compensate for this, they enlist beneficial microbes from their microbiota to defend against pathogens and pests. Pseudomonas, Bacillus, and Trichoderma are well-known plant probiotics that safeguard plants from various stresses. The Phytobiome initiative, launched in 2015, recognizes the importance of plant-microbe communities in crop health and ecosystem balance. In this presentation, we introduce a new probiotic strain called Streptomyces, its interactions with plants and the environment, and its impact on the agroecosystem. Streptomyces, a gram-positive bacterium, is the source of over two-thirds of antibiotics used in human medicine, yet its role and significance in plant and agroecosystem interactions are underestimated. To address this, we initiated the “STreptomyce in Agriculture Research” (STAR) project, focusing on various cropping systems. We employed advanced pyrosequencing platforms to analyze the microbial communities in the rhizosphere and anthosphere. Through this study, we isolated and characterized three putative probiotic Streptomyces strains that were found to colonize the rhizosphere, anthosphere, and phyllosphere. Surprisingly, these three strains exhibited identical genome sequences despite inhabiting different habitats. This raises questions about the existence and function of identical strains in distinct systems. In conclusion, Streptomyces is a ubiquitous and unique microbe that provides beneficial effects to plants and their phytobiome communities. The STAR project holds promising opportunities and possibilities for organic agriculture.