• Mycobiology
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• 제49권5호
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• pp.498-506
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• 2021

An endophytic fungus strain DYSJ3 was isolated from a stem of Aphanamixis grandifolia Blume, which was identified as Aspergillus versicolor based on the morphological characteristics, internal transcribed spacer (ITS) and calmodulin gene sequences analyses. A. versicolor DYSJ3 exhibited strong antagonistic activity against Colletotrichum musae, C. gloeosporioides and Fusarium oxysporum f. sp. cubense with the inhibition rates of 61.9, 51.2 and 55.3% respectively. The antifungal metabolites mainly existed in the mycelium of A. versicolor DYSJ3, and its mycelial crude extract (CE) had broad-spectrum antifungal activities against plant pathogenic fungi. The CE had a good thermal stability, and the inhibition rate of 100 mg/mL CE against C. musae was above 70.0% after disposing at 120 ℃ for 1 h. Five secondary metabolites were isolated from the CE and identified as averufanin, ergosterol peroxide, versicolorin B, averythrin and sterigmatocystin. Activity evaluation showed versicolorin B exhibited inhibitory effects on the mycelial growth and conidial germination of C. musae, and sterigmatocystin had a weak inhibitory effect on the mycelial growth of C. musae.

• BMB Reports
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• 제39권2호
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• pp.158-166
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• 2006

In many organisms, trehalose acts as protective metabolite against harsh environmental stresses, such as freezing, drought, nutrient starvation, heat and salt. Herein a cDNA (designated as GbTPS, GenBank Accession Number AY884150) encoding a trehalose-6-phosphate synthase homologue was isolated and characterized from the living fossil plant, Ginkgo biloba, which is highly tolerant to drought and cold. GbTPS encoded an 868-amino-acid polypeptide with a predicted isoelectric point of 5.83 and molecular mass of 97.9 kD. Amino acid sequence alignment revealed that GbTPS shared high identity with class II trehalose-6-phosphate synthase homologues (67% identical to AtTPS7), but had only 17% and 23% of identity with OstA from Escherichia coli and ScTPS1 from S. cerevisiae, respectively. DNA gel blot analysis indicated that GbTPS belonged to a small multi-gene family. The expression analysis by RT-PCR showed that GbTPS expressed in a tissue-specific manner in G biloba and might involve in leaf development. GbTPS was also found to be induced by a variety of stresses including cold, salt, drought and mannitol.

• Applied Biological Chemistry
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• 제48권1호
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• pp.1-15
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• 2005

농작물이 병해충 및 잡초 등에 의하여 피해를 받게 되면 농업생산성은 상당히 저하된다. 따라서 농업생산성을 높이기 위하여 합성농약을 과용해 왔고, 이로 인하여 토양의 질과 농업환경이 파괴되는 결과를 초래하고 있어서 지속적인 농업이 점차 어려워지고 있다. 오늘날의 농업은 농업환경의 파괴를 최소화하고 농산물의 안전성을 확보함과 동시에 생산성을 증대해야하는 복합적인 문제에 직면해 있다. 한편, 식물은 일반적으로 생존하기 위하며 외부의 침입으로부터 자신을 보호하거나 자신의 영역을 확보하기 위하며 다양한 종류의 2차대사물질을 생산하고 방출한다. 병원균이 침입했을 때 식물이 생산하는 항생물질인 phytoalexin으로는 화본과 식물의 경우 flavonoid계와 diterpenoid계의 물질을 생성하고, 쌍자엽 식물은 감염된 병원균의 종류에 상관없이 Leguminosae과는 flavonoids계, Cruciferae과는 indole 유도체, Solanaceae과는 sesquiterpenoid계, Umbelliferae과는 coumarin계 물질들을 생성하여 병원균에 저항성을 가진다. 곤충의 생리작용을 저해하거나 섭생을 싫어하게 하는 기능의 물질로는 terpene계의 pyrethrin, azadirachtin, limonin, cedrelanoid, toosendanin, fraxinellone/dictamnine 등이 있으며, alkaloid계로서는 terpenoid와 alkaloid가 결합된 sesquiterpene pyridine 및 norditerpenoids alkaloids와 azepine계, amide계, loline계, stemofoline계, pyrrolizidine계 alkaloids 등이 있다. 식물은 또한 자신의 영역을 확보하기 위하여 다른 식물의 생장을 저해하는 물질을 생성하는데 여기에는 terpene계의 essential oil 및 sesquiterpene lactone과 이외에 benzoxazinoids, glucosinolate, quassinoid, cyanogenic glycoside, saponin, sorgolennone, juglone 등 다수의 2차 대사물질들이 있다. 이와 같은 기능의 2차 대사물질을 병해충 및 잡초 방제에 직, 간접으로 이용하는 것은 친환경농업의 한 가지 방법일 수 있다. 그러나 천연물질들은 자연계에서 쉽게 분해되어 효율이 떨어지는 경우가 많고 식물을 통하여 생산하는데도 한계가 있다. 따라서 보다 안전성과 효율성이 뛰어난 2차 대사물질을 찾아내는 연구와 아울러 방제기능이 있는 물질의 생합성경로를 구명하고 대사공학적으로 이용하므로 병해충에 저항성이 있고 잡초 방제효과를 갖는 형질전환 식물을 육성하는 연구가 지속적으로 이루어져야 할 것이다.

• 한국토양비료학회지
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• 제41권1호
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• pp.18-25
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• 2008

배추좀나방 유충의 내장으로부터 분리한 Pseudomons sp. PRGB06의 식물생장촉진능과 생물비료로서의 특성을 연구하였다. 또한 탄소원, 온도, pH, 염류농도 등의 다양한 배양 상태에서 균주의 생장을 확인하였다. 이에 더하여 Pseudomons sp. PRGB06의 진균에 대한 길항기작과 인산가용화능을 연구하였다. PRGB06 균주는 실험에 사용한 대부분의 탄소원에서 잘 자랐으며, 균주 최적 배양조건은 $30^{\circ}C$, pH7이었다. 식물병원성 진균의 억제는 균주로부터 생성된 휘발성 항진균 대사산물과 암모니아 가스로 인한 것으로 사료된다. 또한 균주는 인산가용화와 산의 생성에 크게 관여햐였으며, 뿐만 아니라 공중질소고정, 식물호르몬생성, siderophore생성, 아연가용화 등 다양한 식물생장촉진 특성을 가지고 있는 것으로 확인되었다. 이러한 PRGB06을 고추와 옥수수에 접종한 결과 뿌리길이, 유묘의 생육, 건물량이 증가하였다.

• 한국자원식물학회지
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• 제27권4호
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• pp.271-278
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• 2014

고지혈증은 체내 지질대사에 이상이 생겨 혈중의 지질이 비정상적으로 높아진 상태로서, 지질이 필요 이상으로 혈액내 존재하게 되면 혈관벽에 쌓이고 굳어지게 되면서 동맥경화증, 고혈압, 뇌졸중 등의 심혈관계 질환을 일으키기도 한다. 본 연구에서는 고콜레스테롤 식이로 고지혈증을 유도한 생쥐의 동물모델에서 복분자 추출물의 유효성분인 protocatechuic acid(PCA)를 경구 투여하여 PCA의 간손상 보호 효과와 지질 대사함량 변화를 분석함으로써 PCA의 고지혈증 치료에 대한 유의적인 임상 효과를 제시하였다. PCA의 투여는 고콜레스테롤 식이에 의한 간무게 증가, 비장무게의 증가, 흉선의 위축, 신장의 위축 등 장기무게변화에 대하여 회복 효과를 보였고, 혈청 내 간세포 손상 마커 GPT 및 GOT의 회복 효과를 나타내었으며, 혈청 내 총콜레스테롤, 중성지방, HDL, LDL의 지질대사산물의 profile에서도 유의적인 회복효과를 보였다. 특히, PCA의 투여군에서는 혈중 HDL의 농도를 정상식이군 수준으로 높이고, LDL의 농도를 크게 낮추는 효과를 나타냄으로써 HDL/LDL의 균형유지에 역할을 나타내는 것으로 보이며 이러한 효과는 simvastatin의 HDL/LDL 조절 효과와는 다른 패턴을 보이고 있다. 따라서 PCA는 단독으로 고지혈증 치료의 기능성 소재로써의 개발 가능성뿐만 아니라, 합성의약품 simvastatin 등의 스타틴계 약물의 보조제로써의 개발 가능성을 제시한다.

• 한국환경농학회지
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• 제34권2호
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• pp.111-119
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• 2015

BACKGROUND: Ethychlozate (ECZ) is a plant growth regulator of synthetic auxin for agricultural commodities (ACs). Accurate and sensitive method to determine ECZ in diverse ACs on global official purpose is required to legal residue regulation. As the current official method is confined to the limited type of crops with poor validation, this study was conducted to improve and extend the ECZ method using high-performance liquid chromatography (HPLC) in all the registered crops with method verification. METHODS AND RESULTS: ECZ and its acidic metabolite (ECZA) were both extracted from acidified samples with acetone and briefly purified by dichloromethane partition. ECZ was hydrolyzed to form ECZA and the combined ECZA was finally purified by ion-associated partition including hexane-washing. The instrumental quantitation was performed using HPLC/ FLD under ion-suppression of ECZA with no interference by sample co-extractives. The average recoveries of intra- and inter-day experiment ranged from 82.0 to 105.2% and 81.7 to 102.8%, respectively. The repeatability and reproducibility for intra- and inter-day measurements expressed as a relative standard deviation was less than 8.7% and 7.4%, respectively. CONCLUSION: Established analytical method for ECZ residue in ACs was applicable to the nation-wide pesticide residues monitoring program with the acceptable level of sensitivity, repeatability and reproducibility.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.417-426
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• 2020

Bacillus amyloliquefaciens is an important plant disease-preventing and growth-promoting microorganism. B. amyloliquefaciens WS-8 can stimulate plant growth and has strong antifungal properties. In this study, we sequenced the complete genome of B. amyloliquefaciens WS-8 by Pacific Biosciences RSII (PacBio) Single Molecule Real-Time (SMRT) sequencing. The genome consists of one chromosome (3,929,787 bp) and no additional plasmids. The main bacteriostatic substances were determined by genome, transcriptome, and mass spectrometry data. We thereby laid a theoretical foundation for the utilization of the strain. By genomic analysis, we identified 19 putative biosynthetic gene clusters for secondary metabolites, most of which are potentially involved in the biosynthesis of numerous bioactive metabolites, including difficidin, fengycin, and surfactin. Furthermore, a potential class II lanthipeptide biosynthetic gene cluster and genes that are involved in auxin biosynthesis were found. Through the analysis of transcriptome data, we found that the key bacteriostatic genes, as predicted in the genome, exhibited different levels of mRNA expression. Through metabolite isolation, purification, and exposure experiments, we found that a variety of metabolites of WS-8 exert an inhibitory effect on the necrotrophic fungus Botrytis cinerea, which causes gray mold; by mass spectrometry, we found that the main substances are mainly iturins and fengycins. Therefore, this strain has the potential to be utilized as an antifungal agent in agriculture.

• Journal of Microbiology and Biotechnology
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• 제17권3호
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• pp.414-419
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• 2007

Botryococcus braunii is a green colonial fresh water microalga and it is recognized as one of the renewable resources for production of liquid hydrocarbons. CFTRI-Bb-l and CFTRI-Bb-2 have been reported for the first time and their performance with regard to growth and biochemical profile is presented here. The present study focused on effect of carbon dioxide $(CO_2)$ on biomass, hydrocarbon, carbohydrate production, fatty acid profile, and carotenoid content in various species of B. braunii (LB-572, SAG 30.81, MCRC-Bb, N-836, CFTRI-Bb-l, and CFTRI-Bb-2) at 0.5, 1.0, and 2.0% (v/v) levels using a two-tier flask. $CO_2$ at 2.0% (v/v) level enhanced growth of the organism, and a two-fold increase in biomass and carotenoid contents was observed in all the B. braunii strains studied compared with control culture (without $CO_2$ supplementation). At 1 % and 2% (v/v) $CO_2$ concentrations, palmitic acid and oleic acid levels increased by 2.5 to 3 folds in one of the strains of B. braunii (LB-572). Hydrocarbon content was found to be above 20% at 2% $CO_2$ level in the B. braunii LB-572, CFTRI-Bb-2, CFTRI-Bb-l, and N-836 strains, whereas it was less than 20% in the SAG 30.81 and MCRC-Bb strains compared with control culture. This culture methodology will provide information on $CO_2$ requirement for growth of algae and metabolite production. B. braunii spp. can be grown at the tested levels of $CO_2$ concentration without much influence on culture pH.

• 한국토양비료학회지
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• 제49권4호
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• pp.401-408
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• 2016

The present study described the isolation of 2-methylbutyric acid (2-MBA) produced from Bacillus pumilus L1, to subsequently investigate its nematicidal activity for the control of the root-knot nematode. The results showed that 2-MBA could be purified by chromatographic techniques and was identified using nuclear magnetic resonance and liquid chromatography-mass spectrometry. Crude extract and partially purified compounds had a significant effect on the inhibition of egg hatchability and second-stage juvenile (J2) mortality. A dose-dependent effect of 2-MBA was observed for J2 mortality and egg hatchability. Egg hatchability was 69.2%, 59.9%, 32.7%, and 0.0% at 125, 250, 500, and $1000{\mu}g\;mL^{-1}$ of 2-MBA after 4 d of incubation, respectively. Meanwhile, J2 mortality was in the range of 24.4%-100.0% after 2 d of incubation, depending on the concentrations of 2-MBA used. A pot experiment also demonstrated that treatment of B. pumilus L1 culture caused a significant reduction in the number of galls, egg masses, and J2 population than that of the tap water (TW) control. However, as the B. pumilus L1 culture concentration was decreased, the efficacy of nematode control by treatment of B. pumilus L1 culture was reduced compared to that of TW. B. pumilus L1 inoculation at different concentrations also promoted cucumber plant growth. Therefore, our study demonstrated the potential of 2-MBA from B. pumilus L1 as a biocontrol agent against the root-knot nematode and a plant growth promoter for cucumber plants.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2012년도 정기총회 및 춘계학술발표회
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• pp.8-8
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• 2012

Ginseng have been traditionally used for strengthening immunity, providing nutrition and recovering health from fatigue. Recently, pharmaceutical activities of ginseng roots have been proven by many researches, and ginseng has become a world-famous medicinal plant. Ginseng saponin, ginsenoside, is one of the most important secondary metabolite in ginseng which has various pharmacological activities. Many studies have aimed to convert major ginsenosides to the more active minor ginsenoside Rg3 for consumer demand ginseng product. Microbial strain GS514 strain was isolated from soil around ginseng roots for enzymatic preparation of ginsenoside Rg3, which strain shows strong ability of converting ginsenoside Rb1and Rd into Rg3 in the solution with NaCl. The gene encoding a ${\beta}$-glucosidase from this GS514 was cloned and expressed in the BL21 (DE3) strain of Escherichia coli. The recombinant enzyme was purified and characterized. The molecular mass of purified was 87.5 kDa, as determined by SDS-PAGE. The gene sequence revealed significant homology to the family 3 glycoside hydrolases. The purified single enzyme also catalyzed the conversion of ginsenoside Rb1 into Rg3. This target enzyme will be able to produce as much saponin for consumer demand ginseng product. Anti-apoptotic proteins bind with pro-apoptotic proteins to induce apoptosis mechanism. Over expression of these anti-apoptotic proteins lead to several cancers by preventing apoptosis. Docking simulations were performed for anti-apoptotic proteins with several ginsenosides from Panax ginseng. Our finding shows ginsenosides particularly Rg3, Rh2 and Rf have more binding affinity with apoptotic proteins. Further, these docking system of each ginsenosides can be extended to experimental screen system for further brief confirmations of several diseases.