• 한국토양비료학회지
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• 제44권4호
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• pp.650-656
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• 2011

Lysobacter antibioticus HS124 isolated from pepper rhizosphere soil produced catechol type siderophore. Purified siderophore by Diaion HP-20 and silica gel column chromatography showed several hydroxyl functional groups adjacent to benzene rings by analysis of $^1H$ NMR spectroscopy. The strain HS124 showed different activities to suppress Phytophthora capsici with different concentrations of exogenous Fe (III) in minimal medium where antifungal activity with $100{\mu}M$ Fe (III) was approximately 1.5 times higher than in absence of Fe (III). Bacterial population in this Fe (III)-amended medium was also highest with $8.9{\times}10^8\;CFU\;ml^{-1}$ which also corresponded to the strongest siderophore activity. When grown in rich medium (minimal medium with N, $P_2O_5K_2O$ and glucose), HS124 exhibited approximately 2 times stronger antifungal activity compared to minimal medium. In pot trials, treatments of bacterial culture grown in rich medium with (C1) or without (C2) $100{\mu}M$ Fe (III) exhibited a high protection of pepper plants from disease, compared to medium only with (M1) or without (M2) $100{\mu}M$ Fe (III). Especially, treatment C1 showed the best disease control effect of about 70 %. Thus, the strain HS124 should be recommended as a potential biocontrol agent against P. capsici in pepper.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.13-20
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• 1997

Plant growth-promoting Psudomonas fluorescens GL20 was isolated from a ginseng rhizosphere on chrome azurol Sagar. P. fluorescens GL20 produced a large amount of hydoxamate siderophore in an iron-deficient medium. The siderophore showed significantly high specific activity of 20.2 unit. Using an in vitro antifungal test, P. fluorescens GL20 considerably suppressed growth of phytopathogenic fungus Fusarium solani, inhibiting spore germination and germ tube elongation. In pot trials of kidney beans with P. fluorescens GL20, disease incidence was remarkably reduced up to $68{\%}$ compared with that of F. solani alone, and plant growth was also increased nearly 1.6 fold as compared to that of the untreated control, promoting elongation and development of the roots. These results indicate that the plant growth-promoting activity of P. fluorescens GL20 can play an important role in biological control of soil-borne plant disease in a rhizosphere, enhancing the growth of plants.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.653-657
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• 2004

The cold resistant mutants of P. fluorescens strain $PRS_{9}$ and ATCC13525 were developed which could grow equally well at $28^{\circ}C$ and $10^{\circ}C$. All the mutants were tested for siderophore production, of which $CRPF_9$ (ATCC13525 mutant) was selected, as there was a 16.8-fold increase when compared to its wild-type. Under in vitro conditions, $CRPF_9$ showed better growth promotion both in wheat (29.1% increase in root length) and mung bean (51.5% increase in root length) at $10^{\circ}C$. Greenhouse trials showed a significant increase in root (13.84cm) and shoot (15.0cm) length of $CRPF_9$-treated mung bean seeds, indicating increased rhizocompetence of the mutant. Ferric citrate was a better iron source than ferric hydroxide for plant growth.

• Journal of Ginseng Research
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• 제7권2호
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• pp.102-107
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• 1983

The effects of saponin, one of major components (Panax ginseng C.A. Meyer), on the growth of E. coli K-12 and the formation of siderphore was observed The following results were obtained. 1. When E. coli was grown on medium containing 1${\times}$10-5%-11${\times}$10-1% of the saponin, the rate of growth was stimulated at 10-1% of the saponin significantly compared to that of control. 2. When E. coli K-12 was grown on medium containing 1${\times}$10-1% of the saponin, the amount of siderphore was two times as much as the control. 3. The growth of E. coli was observed to be dependent on the concentration of siderophore when siderophore was added to medium. 4. The effect of saponin on the formation of siderophore in vitro was observed to reach maximum at 1${\times}$10-3% of the saponin. Such results suggest that the growth rate of E. coli K-12 could be enhanced by ginseng saponin fraction through stimulation of siderphore formation. We have described the fast growth of E. coli, K-12 and B. subtilis, rapid uptake of 14C-glucose, and high level of other metabolites such as lipids and proteins of E. coli, and B. subtilis in medium containing saponing fraction compared to that of microorganisms without saponin fraction.1∼3Such differences were claimed to be due to rapid uptake of 14C-glucose by widened periplasmic region throught unknown mechanism in the prescence of saponin fraction in medium3 and have raised a question whether there is another possible factor, siderophore4(Greek for iron bears), since microorganisms must secure a sufficient amount of iron for normal growth. These are known to be synthesized by the cells under iron-deficient condition and in most case, excreted into the medium5, where they can complex and solubilize any iron present there. It is generally believed that these complexes are then taken into the cells presumably by specific transport systems, thus providing iron for cell metabolism. Within the group of enteric bacteria, only three species (E. coli, S. typhimurium, and A. aerogense) have, so far, been studied in a ny detail. The main iron-binding compound produced by these species is enterochelin, and its role in iron transport is now well established. And biosynthesis of enterochelin from 2, 3- dihydroxybenzoate and serine in the prescence of magnesium ions and ATP was reported6. 2, 3-dihydroxybenzoate was also shown to involve isochorismate and 2, 3-dihydro-2, 3-dihydroxybenzoate as intermediate.7∼11 The present paper deals with the effect of ginseng saponin fraction on growth, the level of enterochelin formation in vivo and the conversion of 2, 3-dihydroxybenzoate and serine into entrochelin in vitro, and entrochelin obtained on the growth in relation to possible explanation of ginseng saponin fraction on the rapid growth of E. coli, K-12.

• 원예과학기술지
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• 제33권4호
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• pp.492-500
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• 2015

본 연구는 한국잔디에 발생하는 주요 병해인 갈색퍼짐병 억제능력을 보인 3가지 길항 미생물의 길항기작과 미생물제제의 개발에 필요한 배양 조건을 밝히는 것이다. 길항미생물들의 길항작용 기작인chitinase, cellulase 및 siderophore생산능 조사에서 선발 길항미생물 모두 chitinase 활성은 없었으나, I-009균주와 FRIN-001-1균주에서 cellulase와 siderophore의 활성이 있어 진균의 외막가수분해 및 경쟁적 길항작용이 있다고 판단하였다. 그러나 YPIN-022균주는 siderophore의 생산능은 확인하였으나, chitinase와 cellulase의 생산능은 없는 것으로 확인되었다. 선발 길항미생물의 실용화를 위해서는 대량 배양이 필수적이므로 배양학적 특징을 탐색하고자 배지, 온도, pH, 배양시간, 탄소원, 질소원, 무기화합물 등의 영향을 조사한 결과 세 균주 모두 LB 배지에서 생육이 가장 왕성하였다. 최적 배양 온도는 I-009와 FRIN-001-1균주는 pH 5-8범위에서 $35^{\circ}C$와 $30^{\circ}C$ 온도로 32시간 및 28시간 배양할 때 각각 균체의 생장이 가장 높았다. Pseudomonas 속의 YPIN-022균주는 $35^{\circ}C$ 배양 온도로 pH 5-9 배지위에서 24시간 배양시킬 때 생육이 가장 높았다. 탄소원으로 1% sucrose, 질소원으로 0.5% 효모추출물, 무기화합물로 0.1% 염화칼륨을 첨가한 배지에서 I-009와 YPIN-022균주의 생육이 가장 좋았으나, FRIN-001-1균주는 탄소원으로 mannitol, 무기화 합물로 인산칼륨 첨가배지에서 생육이 더 양호했다.

• Applied Biological Chemistry
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• 제50권1호
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• pp.23-28
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• 2007

작물의 생육촉진과 식물 진균병의 생물방제능 효과를 동시에 나타내는 다기능 유기농업용 미생물제제를 개발하고자 경북지역 저병해 경작지 토양으로부터 옥신생산성 균주들을 분리하였다. 그 중 auxin, siderophore, 그리고 항진균성 cellulase를 동시에 생산하는 K11 균주를 선발하였으며, 선발된 K11 균주는 형태 및 생화학적 test 후 Biolog사의 동정시스템(Microlog$^{TM}$ 4.0)과 16s rDNA 상동성을 조사한 결과 Bacillus licheniformis로 동정되었으며, 이를 Bacillus licheniformis K11로 명명하였다. B. licheniformis K11은 고추역병의 원인균인 Phytophthora capsici에 대하여 in vitro 상에서 63%의 길항능을 보였으며, in vivo pot test에서도 뛰어난 방제능을 나타내었다. 또한 B. licheniformis K11의 배양액을 10ml/l로 처리한 녹두발근생검법에서 시판중인 IAA(0.1 mg/l)보다 발근율이 15% 증가됨을 확인 할 수 있었다. 또한 배추, 완두, 녹두를 대상으로 B. licheniformis K11에 의한 식물 생장촉진을 조사한 결과 녹두, 완두 그리고 배추의 뿌리 생육을 각각 160, 150, 130% 증가시켰다. 상기 연구 결과들로 미루어 볼 때 다기능 생물방제균인 B. licheniformis K11을 경작지에 관주하거나 적합한 미생물제제로 제제화한다면 토양전염성 질병의 방제와 함께 옥신 생산성에 의한 작물생육의 촉진으로 수확시기를 조기화 함으로 농가에 수익 증대 효과를 줄 수 있을 것이므로 친환경 농업용 미생물제제로 개발 가능성이 있음을 확인 할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제21권6호
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• pp.556-566
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• 2011

A total of 31 Acinetobacter isolates were obtained from the rhizosphere of Pennisetum glaucum and evaluated for their plant-growth-promoting traits. Two isolates, namely Acinetobacter sp. PUCM1007 and A. baumannii PUCM1029, produced indole acetic acid (10-13 ${\mu}g$/ml). A total of 26 and 27 isolates solubilized phosphates and zinc oxide, respectively. Among the mineral-solubilizing strains, A. calcoaceticus PUCM1006 solubilized phosphate most efficiently (84 mg/ml), whereas zinc oxide was solubilized by A. calcoaceticus PUCM1025 at the highest solubilization efficiency of 918%. All the Acinetobacter isolates, except PUCM1010, produced siderophores. The highest siderophore production (85.0 siderophore units) was exhibited by A. calcoaceticus PUCM1016. Strains PUCM1001 and PUCM1019 (both A. calcoaceticus) and PUCM1022 (Acinetobacter sp.) produced both hydroxamate-and catechol-type siderophores, whereas all the other strains only produced catechol-type siderophores. In vitro inhibition of Fusarium oxysporum under iron-limited conditions was demonstrated by the siderophore-producing Acinetobacter strains, where PUCM1018 was the most potent inhibitor of the fungal phytopathogen. Acinetobacter sp. PUCM1022 significantly enhanced the shoot height, root length, and root dry weights of pearl millet seedlings in pot experiments when compared with controls, underscoring the plant-growth-promoting potential of these isolates.

• Journal of Ginseng Research
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• 제45권1호
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• pp.156-162
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• 2021

Background: It is estimated that 20-30% of ginseng crops in Canada are lost to root rot each harvest. This disease is commonly caused by fungal infection with Ilyonectria, previously known as Cylindrocarpon. Previous reports have linked the virulence of fungal disease to the production of siderophores, a class of small-molecule iron chelators. However, these siderophores have not been identified in Ilyonectria. Methods: High-resolution LC-MS/MS was used to screen Ilyonectria and Cylindrocarpon strain extracts for secondary metabolite production. These strains were also tested for their ability to cause root rot in American ginseng and categorized as virulent or avirulent. The differences in detected metabolites between the virulent and avirulent strains were compared with a focus on siderophores. Results: For the first time, a siderophore N,N',N"-triacetylfusarinine C (TAFC) has been identified in Ilyonectria, and it appears to be linked to disease virulence. Siderophore production was suppressed as the concentration of iron increased, which is in agreement with previous reports. Conclusion: The identification of the siderophore produced by Ilyonectria gives us further insight into the root rot disease that heavily affects ginseng crop yields. This research identifies a molecular pathway previously unknown for ginseng root rot and could lead to new disease treatment options.

• Journal of Ginseng Research
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• 제45권2호
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• pp.218-227
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• 2021

Background: Panax ginseng is one of the most important medicinal plants and is usually harvested after 5 to 6 years of cultivation in Korea. Heavy metal (HM) exposure is a type of abiotic stress that can induce oxidative stress and decrease the quality of the ginseng crop. Siderophore-producing rhizobacteria (SPR) may be capable of bioremediating HM contamination. Methods: Several isolates from ginseng rhizosphere were evaluated by in vitro screening of their plant growth-promoting traits and HM resistance. Subsequently, in planta (pot tests) and in vitro (medium tests) were designed to investigate the SPR ability to reduce oxidative stress and enhance HM resistance in P. ginseng inoculated with the SPR candidate. Results: In vitro tests revealed that the siderophore-producing Mesorhizobium panacihumi DCY119^T had higher HM resistance than the other tested isolates and was selected as the SPR candidate. In the planta experiments, 2-year-old ginseng seedlings exposed to 25 mL (500 mM) Fe solution had lower biomass and higher reactive oxygen species level than control seedlings. In contrast, seedlings treated with 10⁸ CFU/mL DCY119^T for 10 minutes had higher biomass and higher levels of antioxidant genes and nonenzymatic antioxidant chemicals than untreated seedlings. When Fe concentration in the medium was increased, DCY119^T can produce siderophores and scavenge reactive oxygen species to reduce Fe toxicity in addition to providing indole-3-acetic acid to promote seedling growth, thereby conferring inoculated ginseng with HM resistance. Conclusions: It was confirmed that SPR DCY119^T can potentially be used for bioremediation of HM contamination.

• Archives of Pharmacal Research
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• 제29권3호
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• pp.249-255
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• 2006

Ability of iron acquisition of pathogenic microorganisms functions as a virulence factor. Candida albicans, a fungal pathogen that requires iron for growth, is susceptible to growth retardation by high-affinity iron binding proteins such as transferrin. Recently, we reported that C. albicans could utilize the heme as a part of heme-containing proteins dissociated by heme oxygenase, CaHMX1. In search of another pathway that C. albicans can use to bypass the growth regulation produced by iron limitation, this present study examined utilization of non-candidal siderophores such as Desferal and rhodotorulic acid (RA) for acquisition of inorganic iron by the fungus. C. albicans secreting no siderophores was cultured in iron-free (pretreated with apotransferrin for 24 h) (culture medium). Once growth of the yeast reached stasis from iron starvation, a siderophore was added to the culture media. Results showed that cultures containing apotransferrin within a dialysis membrane recovered growth to the level of untreated controls, whereas C. albicans yeast cells in direct contact with soluble iron-free (apo) transferrin recovered growth only partially. When static growth from iron limitation was reached, the addition of siderophore-apotransferrin complex to culture medium also permitted the yeast to recover growth from apotransferrin growth regulation. All the data show that C. albicans can utilize the non-candidal siderophores for iron acquisition under transferrin regulation as can pathogenic bacteria.