• BMB Reports
• /
• 제29권5호
• /
• pp.429-435
• /
• 1996

To investigate the structure-antagonistic relationship of the cyclohexapeptide L-659,877, a selective NK-2 tachykinin receptor antagonist, seven analogues were chemically synthesized by a solid phase method. The agonistic and antagonistic activities of the analogues were evaluated by contraction assay using the smooth muscle of guinea pig trachea (GPT) containing the NK-2 receptor. It was shown that the aromatic ring of Phe at position 3 and the sulfur group of Met at position 6 in L-659,877 were essential for binding to the NK-2 receptor. Decrease in antagonistic activity of L-659,877 caused by substituting Leu for Nle at position 5 indicates that the ${\gamma}$ methyl group and side chain length of Leu plays an important role in its antagonistic action. Although the activity was slightly lower than L-659,877, cyclo $[{\beta}Ala^{8}]NKA(4-10)$ (analogue 1) showed potential antagonistic activity for the NK-2 receptor. It was confirmed that the expansion of the ring in L-659,877 by substitution of ${\beta}Ala$ for Gly at position 4 stabilized its conformation monitored by CD spectra. The results suggest that analogue 1 can be used as a new leader compound to design a more powerful, selective, and stable NK-2 receptor antagonist.

• 한국유기농업학회지
• /
• 제6권1호
• /
• pp.133-149
• /
• 1997

Recently, the importance of management and cultivation of grasses has been increased in Korea. Among these cultural practices, the appropriate control of diseases is considered more important than other cultivation techniques such as fertilization and irrigation. The damages of brown patch and large patch caused by Rhizoctonia spp. and Pythium blight caused by Pythium spp. are serious in the major cultivation area of turfgrass in Korea. Since these diseases are difficult to control by agrochemicals, the damages are very serious if these are occured. The periodic spray of agrochemicals, to protect and control these diseases could make some problems of toxicity and environmental pollution as well as rising of non-target diseases. Therefore, the biological methods to control diseases have been required to decrease problems resulted from overuse of agrochemicals, to conserve natural ecosystem, and to control effectively diseases of grasses in the long period. The number of studies about biological control using antagonistic microorganisms have been increased for last half century. However, the application of biological control method has been very limited. In this study, thirteen isolates of R. cerealis, 8 isolates of R. solani and 3 isolates of Phthyn spp. have been isolated from diseased turfgrass in golf course and grass-culture area that have patch and wilting symptoms of zoysia grass and creeping bentgrass. Isolation frequency of R. cerealis and R. solani was high in especially zoysiagrass, while Pythym spp. was isolated from bent grass at low frequency but showed high pathogenicity. Totally, 205 isolates of soil microorganisms were isolated in this study as primary antagonistic microorganism by Herr's triple agar layer plate and dual culture method using rhizosphere of grasses, soil of crop field as the source of antagonistic microorganisms. Among the 205 isolates, 23 isolates were actinomycetes and 182 isolates were bacteria. All of the actinomycetes were isolated by Herr's method. Antagonistic effect of primary isolated microorganisms was tested for in vitro mycelial growth inhibition against pathogenic fungi isolated from grasses and for inhibition of disease occurrence in 24 well tissue culture plate and pot experiment. Then, four isolated of bacteria which are BG23, BG74, BG136 and BG171 were selected as antagonistic microorganisms against soil-born pathogenic fungi of bentgrass.

• The Plant Pathology Journal
• /
• 제31권1호
• /
• pp.50-60
• /
• 2015

The use of novel isolates of Trichoderma with efficient antagonistic capacity against Fusarium oxysporum f. sp. lycopersici (FOL) is a promising alternative strategy to pesticides for tomato wilt management. We evaluated the antagonistic activity of 30 isolates of T. asperellum against 4 different isolates of FOL. The production of extracellular cell wall degrading enzymes of the antagonistic isolates was also measured. The random amplified polymorphic DNA (RAPD) method was applied to assess the genetic variability among the T. asperellum isolates. All of the T. asperellum isolates significantly reduced the mycelial growth of FOL isolates but the amount of growth reduction varied significantly as well. There was a correlation between the antagonistic capacity of T. asperellum isolates towards FOL and their lytic enzyme production. Isolates showing high levels of chitinase and ${\beta}$-1,3-glucanase activities strongly inhibited the growth of FOL isolates. RAPD analysis showed a high level of genetic variation among T. asperellum isolates. The UPGMA dendrogram revealed that T. asperellum isolates could not be grouped by their antagonistic behavior or lytic enzymes production. Six isolates of T. asperellum were highly antagonistic towards FOL and potentially could be used in commercial agriculture to control tomato wilt. Our results are consistent with the conclusion that understanding the genetic variation within Trichoderma isolates and their biochemical capabilities are required for the selection of effective indigenous fungal strains for the use as biocontrol agents.

• 한국초지조사료학회지
• /
• 제18권2호
• /
• pp.133-142
• /
• 1998

This study was conducted to investigate the effects of antagonistic bacteria and pathogenic fungi on the growth of tall fescue(Festuca arundinacea Schreb.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). Tall fescue was established by seeding into pots of 11 cm in diameter and 9 cm in depth containing 1 : 1 mixture of soil and vermiculite, and cultivated at pots with antagonistic bacteria and pathogenic fungi in a vinyl house. The bacteria used in this study were Bacillus subtilis and hsants. B. subtilis was isolated and identified kern forage rhizosphere soil and fusants were isolated through cell hsion from B. subtilis and B. thwingiensis. B. subtilis was named as B. subtilis 101 and hsants were named as F-3, F-7 and F-8. In dark culture experiment, tall fescue inoculated with the antagonistic bacteria lived longer than that of control in both CCS and NCCS. However, tall fescue of CCS lived shorter than that of NCCS. Dry weight of tall fescue inoculated with the antagonistic bacteria was higher than that of tall fescue inoculated with pathogenic hngi in both CCS and NCCS(P< 0.05), and the antagonistic bacteria showed positive effects on the growth of tall fescue. However, Dry weight of tall fescue was decreased by the inoculation of the pathogenic b g i in both CCS and NCCS(P< 0.05).

• 한국미생물·생명공학회지
• /
• 제47권2호
• /
• pp.183-194
• /
• 2019

The consumption of fresh vegetables has been related to recurrent outbreaks of foodborne diseases (FBD) worldwide. Therefore, the development of effective alternative technologies is necessary to improve the safety of these products. This study aimed to isolate and identify epiphytic lactic acid bacteria (LAB) from fresh fruits and leafy vegetables and characterize their antagonistic capacity due to their ability to produce bacteriocins or antibacterial compounds. For this, 92 LAB isolates from fruits and leafy vegetables were screened for antagonistic activity. Two strains with the highest and broadest antagonistic activities were selected for further characterization; one from cantaloupe melon (strain CM175) and one from cilantro leaves (strain C15). The cell-free supernatants (CFS) of CM175 and C15 were found to exhibit antagonistic activity against FBD-causing pathogens. The CM175 and C15 strains were identified as Pediococcus pentosaceus and Lactobacillus graminis, respectively. Notably, the P. pentosaceus CM175 CFS stopped the growth of Salmonella Typhimurium, Salmonella Saintpaul, Staphylococcus aureus, and Listeria monocytogenes, and delayed Escherichia coli O157:H7 growth. Moreover, L. graminis C15 CFS delayed the growth of all indicator pathogens, but did not completely stop it. Organic acids and bacteriocin-like molecules were determined to be possibly exerting the observed antagonistic activity of the identified LAB strains. Thus, application of the antagonistic compounds produced by Pediococcus pentosaceus and Lactobacillus graminis could be a novel and ecological strategy in developing antimicrobial biopreservatives for the food industry and mitigating FBD by reducing the biological contamination in fruit and vegetable orchards, mainly via their potential in controlling both gram-negative and gram-positive pathogenic bacteria.

• 식물병연구
• /
• 제24권3호
• /
• pp.213-220
• /
• 2018

섬유소 분해 점액세균인 Sorangium cellulosum 균주들 중 Botrytis cinerea에 길항력을 갖는다고 보고한 4균주(Antagonistic to Botrytis, AB 계열)와 Colletotrichum acutatum에 길항력을 갖는다고 보고한 2균주(Antagonistic to Colletotrichum, AC 계열)를 5가지(A-E)의 S. cellulosum 아종(subspecies)으로 분류하였다. 분류 기준 유전자인 xynB1, bglA2, groEL1 세 유전자의 유전자 유무 및 염기서열 분석을 통해 AB 계열은 아종 C, AC 계열은 아종 D로 분류하였다. 또한, 배양추출물을 고효율 액체크로마토그래피(HPLC)로 분석한 아종 분류 결과 AB 계열 4균주는 머무름시간 20-22.5분에 유사한 특징 피크가 나타난 반면, AC 계열인 2균주는 특징 피크가 없으므로 AB 계열은 아종 C, AC 계열은 아종 D임을 재확인하였다. AB 계열 4균주들의 배양여액을 사용하여 방울토마토에 전처리 후 B. cinerea를 접종한 생물검정으로 방제가와 크로마토그램 특징 피크의 상대 면적값과의 상관분석 결과, 피크 면적이 큰 균주일수록 방제가도 높은 양의 상관관계($R^2=0.9652$)를 확인하였다. 아종 분류 결과 AB 계열은 아종 C의 대표 생리활성 물질의 파생물인 epothilone D로 추정되어, 이를 표준시료로 HPLC 분석한 결과 epothilone D의 머무름시간은 9.9분이었던 반면, KYC 3270 특성 피크의 머무름시간은 11.581분으로 달랐다. 따라서 우리는 AB 계열이 분비하는 생리활성 물질은 epothilone의 파생물인 7-ketone epothilone D로 추정하였다.

• 식물병연구
• /
• 제28권2호
• /
• pp.69-81
• /
• 2022

본 연구에서는 수박에서 과실썩음병을 유발하는 Acidovorax citrulli를 억제하는 세균을 선발하고, 선발한 세균이 성장촉진 및 길항 효소를 생성하는지 확인하였다. 전국 26개 지역의 94곳의 수박재배지와 25곳의 대형 원예 육묘장에서 수박 식물체(잎, 꽃, 뿌리) 및 토양을 수집하였다. 수집한 sample에서 tryptic soy agar와 yeast extract peptone dextrose 배지에서 각각 1,953종과 841종 총 2,794종의 미생물을 분리하였으며, 2,794종의 미생물 중 2종의 A. citrulli를 선발하였다. 선발한 A. citrulli에 대한 기내 길항성 검정 결과 3-3B에서 24종, 9-4B에서 14종 총 28종의 길항 세균을 선발하였다. 선발한 길항 세균 중 BNPL-6-3B, HYGPL-1-3B, TIPL-6-1B, YGMP-2-7Y는 2종의 bacterial fruit blotch균 모두에서 강한 길항성을 보였다. 선발한 28종의 길항 세균을 대상으로 총 6가지의 생화학적 검증을 진행하였으며, 선발한 길항 세균 중 CB20R-2-5B, TIPL-4-2B, TIPL-6-1B, TIPL-7-4B 4가지 균주가 5가지의 생화학적 검증에서 성장촉진 및 길항 효소를 분비하는 것을 확인하였다. 또한, BNPL-3-3B와 BNPL-6-3B 두 균주는 성장촉진 효소 분비를 확인하는 4가지의 생화학적 검증(ammonia production, phosphate solubilization, starch hydrolysis, siderophore production)에서 모두에서 효소를 분비하는 것으로 확인되었다. 본 연구에서 선발한 28종의 길항 세균은 배지에서 A. citrulli를 효과적으로 억제하였으며, 사이안화 수소와 단백질분해효소 생산 능력 검정을 통해 길항 활성을 확인하였다. 또한, 선발한 길항 세균의 암모니아 생산 및 불용성 인산 가용화 능력을 확인하여 식물 성장촉진 활성을 가지는 것으로 확인하였다. 따라서, 본 연구결과는 향후 수박 과실썩음병 방제제 및 성장촉진제 등의 친환경 농자재 개발에 유용한 기초 자료가 될 것으로 판단된다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2012년도 추계학술대회 논문집
• /
• pp.57-58
• /
• 2012

• 한국가금학회지
• /
• 제6권1호
• /
• pp.47-50
• /
• 1979

본고는 미량광물질(동, 아연, 철. 크롬 등)의 길항성 (Antagonistic) 상호관계에 대한 저자의 발표논문에서 발췌한 것으로 크롬(Cr)의 함량이 높은 피혁분의 이용성제고, 그리고 수은 등에 의한 음수 오염에서 오는 닭의 성장저해의 대책을 제시하여 줄 수 있는 귀중한 자료로 생각된다. ㆍㆍㆍㆍ(주)

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2010년도 춘계학술대회 논문집
• /
• pp.317-318
• /
• 2010