• The Plant Pathology Journal
• /
• 제25권4호
• /
• pp.369-375
• /
• 2009

The potential antiviral effects of the culture filtrates (CF) from Serratia marcescens strain Gsm01 against yellow strain of Cucumber mosaic virus (CMV-Y) were investigated. The culture filtrate of S. marcescens strain Gsm01 applied on Chenopodium amaranticolor showed high inhibitory activity, likewise no necrosis appeared when applied on the tobacco plants 2 days before CMV-Y inoculation. When plants were challenge inoculated with CMV-Y for eighteen days, the disease incidence in plants with culture filtrate of S. marcescens Gsm01 did not exceed 59%, whereas 100% of control plants were severely infected. The results of double antibody sandwich-enzyme linked immunosorbent assay (DAS-ELISA), reverse transcriptase polymerase chain reaction (RT-PCR), dot blotting, and western blotting showed that culture filtrate treatment highly affected the accumulation of CMV-Y or its CP protein gene in the treated plant leaves. It was also observed that the culture filtrate had no RNase activity on genomic RNAs of CMV-Y, suggesting that culture filtrate may not contain ribosome inactivating proteins (RIPs) or proteins with RNase activity. These data shows that culture filtrate of S. marcescens strain Gsm01 seems to be a promising source of antiviral substance for the practical use.

• 생태와환경
• /
• 제49권3호
• /
• pp.176-186
• /
• 2016

For several decades, lactic acid bacterium (Lactobacillus graminis: LAB) has been generally recognized as safe. To develop the pan-environmental bio-control agent, algicidal activity of the live LAB cell and its culture filtrate (CF) was examined against Microcystis aeruginosa. LAB cells perfectly lysed M. aeruginosa within 3 days, while the CF had a less effect than the live cells, approximately 78% inhibition of algal growth during a same culture period. The concentration of microcystin in alone culture of M. aeruginosa was $7.1{\mu}gL^{-1}$, but gradually increased and leach $158.5{\mu}gL^{-1}$ on 10 days. However, LAB cells clearly decreased the microcystin by $10.3{\mu}gL^{-1}$ in the same period, approximately 93.5%. CF of LAB showed a strong algicidal activity over 75% between pH 2-7, 91.3% by the treatment of proteinase K, 87.8% by below 3 kDa in particle size, and 75.3% by heat treatment, respectively. Of five solvents, fractions of CF passed through solvents diethyl ether and ethyl acetate showed an obvious algicidal activity in the algal-lawn test. Among 5 fractions purified by silica-gel TLC plate, two spots showed a most strong removal activity on M. aeruginosa. Another analysis of GC indicate that CF contained six representative fatty acids. Even though most of these substance have been known as an anti-algal substance against M. aeruginosa, oleic acid is the most effective. These results suggested that the culture filtrate or specific substances, like a fatty acids, in comparison with live L. graminis can be a successful and eco-friendly agent to control Microcystis bloom.

• The Plant Pathology Journal
• /
• 제38권1호
• /
• pp.33-45
• /
• 2022

To screen antagonistic fungi against plant pathogens, dual culture assay (DCA) and culture filtrate assay (CFA) were performed with unknown soil-born fungi. Among the different fungi isolated and screened from the soil, fungal isolate ANU-301 successfully inhibited growth of different plant pathogenic fungi, Colletotrichum acutatum, Alternaria alternata, and Fusarium oxysporum, in DCA and CFA. Morphological characteristics and rDNA internal transcribed spacer sequence analysis identified ANU-301 as Aspergillus terreus. Inoculation of tomato plants with Fusarium oxysporum f. sp. lycopersici (FOL) induced severe wilting symptom; however, co-inoculation with ANU-301 significantly enhanced resistance of tomato plants against FOL. In addition, culture filtrate (CF) of ANU-301 not only showed bacterial growth inhibition activity against Dickeya chrysanthemi (Dc), but also demonstrated protective effect in potato tuber against soft rot disease. Gas chromatography-tandem mass spectrometry analysis of CF of ANU-301 identified 2,4-bis(1-methyl-1-phenylethyl)-phenol (MPP) as the most abundant compound. MPP inhibited growth of Dc, but not of FOL, in a dose-dependent manner, and protected potato tuber from the soft rot disease induced by Dc. In conclusion, Aspergillus terreus ANU-301 could be used and further tested as a potential biological control agent.

• Mycobiology
• /
• 제47권1호
• /
• pp.87-96
• /
• 2019

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of whiterot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.

• 농약과학회지
• /
• 제10권4호
• /
• pp.344-350
• /
• 2006

항바이러스 효과를 나타내는 세균은 강원도 홍천 인삼재배지의 수삼으로부터 분리하였다. 분리세균은 생리 생화학 테스트와 16s rRNA 유전자 분석을 통해 동정한 결과, Serratia 속으로 동정 되어져 본 세균을 Gsm01으로 명명하였다. Gsm01 균주를 MGY 액체배지에 증식시켜 배양 여액을 0.45 ${\mu}m$ filter에 통과시킨 Culture filtrate (CF)를 명아주 (Chenopodium amaranticolor)에 반엽법으로 처리한 결과, 오이모자이크 바이러스 (CMV)에 대한 억제율이 98%로 매우 높은 것을 확인하였다. 또한 전신유도저항성을 확인하기 위하여 담배 (Nicotiana tabacum cv. Xanthi-nc)의 하엽에 CF와 CMV-Y를 처리하였을 때, CF를 처리한 식물에서 접종15일 후까지 바이러스 증상이 관찰되지 않았다. 고추의 포장시험에서 무처리 식물과 비교해 보았을 때 바이러스 증상은 52.9% 감소한 것으로 보아 포장 시험에서 CF를 처리한 농작물의 산출량이 무처리 식물에 비해 14% 증가함을 확인 할 수 있었다. 한편, Gsm01 균주의 CF는 고추에 어떠한 약해도 나타내지 않아 매우 안전한 것으로 판단되었다.

• 한국균학회지
• /
• 제49권4호
• /
• pp.433-440
• /
• 2021

The fungal genus Trametes is globally distributed and comprises various wood-decay species, including the well-known medicinal mushroom Trametes versicolor, a popular remedy in traditional Asian medicine. Trametes species produce antioxidants, which have a wide range of health benefits. The pressent study evaluated seven indigenous Trametes species from Korea, which were cultivated in three different media (dextrose-yeast extract, DY; malt extract-yeast extract, MY; malt extract broth, MEB) and tested for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. We found that the medium consumption rate did not significantly differ between the media and among the strains (72-76%). However, the T. versicolor strains had a relatively low consumption rate (14-65%). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) tests demonstrated that culture filtrates of T. cf. junipericola, T. orientalis, T. suaveolens, and T. versicolor possessed antioxidant activity against damage from free radicals. In particular, T. cf. junipericola (DY) and T. versicolor (MY) had >80% activity in the DPPH and ABTS assays, compared with that of the positive control (ascorbic acid). Thus, our study identified promising candidates with substantial antioxidant activity among the indigenous strains of Trametes spp. from Korea.

• Journal of Ginseng Research
• /
• 제38권2호
• /
• pp.136-145
• /
• 2014

Background: This study aimed to develop a biocontrol system for ginseng root rot caused by Fusarium cf. incarnatum. Methods: In total, 392 bacteria isolated from ginseng roots and various soils were screened for their antifungal activity against the fungal pathogen, and a bacterial isolate (B2-5) was selected as a promising candidate for the biocontrol because of the strong antagonistic activity of the bacterial cell suspension and culture filtrate against pathogen. Results: The bacterial isolate B2-5 displayed an enhanced inhibitory activity against the pathogen mycelial growth with a temperature increase to $25^{\circ}C$, produced no pectinase (related to root rotting) an no critical rot symptoms at low [$10^6$ colony-forming units (CFU)/mL] and high ($10^8CFU/mL$) inoculum concentrations. In pot experiments, pretreatment with the bacterial isolate in the presumed optimal time for disease control reduced disease severity significantly with a higher control efficacy at an inoculum concentration of $10^6CFU/mL$ than at $10^8CFU/mL$. The establishment and colonization ability of the bacterial isolates on the ginseng rhizosphere appeared to be higher when both the bacterial isolate and the pathogen were coinoculated than when the bacterial isolate was inoculated alone, suggesting its target-oriented biocontrol activity against the pathogen. Scanning electron microscopy showed that the pathogen hyphae were twisted and shriveled by the bacterial treatment, which may be a symptom of direct damage by antifungal substances. Conclusion: All of these results suggest that the bacterial isolate has good potential as a microbial agent for the biocontrol of the ginseng root rot caused by F. cf. incarnatum.

• Journal of Microbiology and Biotechnology
• /
• 제20권1호
• /
• pp.202-207
• /
• 2010

Plant growth promoting fungi (PGPF) are well known for the production of useful secondary metabolites. However, limited information is available on the gibberellin (GA) production capacity of PGPF of endophytic origin. In the current study, 15 fungal endophytes were isolated from the roots of Crown daisy, and then screened on Waito-c rice, in order to identify plant growth promoting fungi. The fungal isolate MH7 significantly increased the shoot length (12.1 cm) of Waito-c in comparison with control treatment (7.9 cm). In a separate experiment, the culture filtrate (CF) of MH7 significantly promoted the growth attributes of Crown daisy. The MH7 CF was analyzed for gibberellins and it contained all physiologically active gibberellins ($GA_1$, 1.37 ng/ml; $GA_3$, 5.88 ng/ml; $GA_4$, 8.62 ng/ml; and $GA_7$, 2.05 ng/ml) in conjunction with physiologically inactive $GA_9$ (0.83 ng/ml), $GA_{12}$ (0.44 ng/ml), $GA_{15}$ (0.74 ng/ml), $GA_{19}$ (1.16 ng/ml), and $GA_{20}$ (0.98 ng/ml). The CF of MH7 produced higher amounts of $GA_3$, $GA_4$, $GA_7$, $GA_9$, and $GA_{12}$ than wild-type Fusarium fujikuroi, which was used as a control for GA production. The fungal isolate MH7 was later identified as a new strain of Penicillium on the basis of its morphological characteristics and phylogenetic analysis of the 188 rDNA sequence.

• The Plant Pathology Journal
• /
• 제29권2호
• /
• pp.193-200
• /
• 2013

Trichoderma asperellum SKT-1 is a microbial pesticide that is very effective against various diseases. Our study was undertaken to evaluate T. asperellum SKT-1 for induction of resistance against yellow strain of Cucumber mosaic virus (CMV-Y) in Arabidopsis plants. Disease severity was rated at 2 weeks post inoculation (WPI). CMV titre in Arabidopsis leaves was determined by indirect enzyme-linked immunosorbent assay (ELISA) at 2 WPI. Our results demonstrated that among all Arabidopsis plants treated with barley grain inoculum (BGI) of SKT-1 NahG and npr1 plants showed no significant reduction in disease severity and CMV titre as compared with control plants. In contrast, disease severity and CMV titre were significantly reduced in all Arabidopsis plants treated with culture filtrate (CF) of SKT-1 as compared with control plants. RT-PCR results showed increased expression levels of SA-inducible genes, but not JA/ET-inducible genes, in leaves of BGI treated plants. Moreover, expression levels of SA- and JA/ET-inducible genes were increased in leaves of CF treated plants. In conclusion, BGI treatment induced systemic resistance against CMV through SA signaling cascade in Arabidopsis plants. While, treatment with CF of SKT-1 mediated the expression of a majority of the various pathogen related genes, which led to the increased defense mechanism against CMV infection.

• 한국균학회지
• /
• 제17권2호
• /
• pp.66-75
• /
• 1989

임상가검물(臨床可檢物)로부터 분리(分離)된 Aspergillus fumigatus 균주(菌株)의 항원조성(抗原造成)과 이균에 감염(感染)된 환자의 항체반응(抗體反應)의 다양성을 Immunoblotting으로 관찰하였다. SDS-PAGE와 immunoblots상에 나타난 결과를 보면 비교분석된 배양려액항원(培養慮液抗原)의 조성에 있어서 균주간(菌株間)에 정성(定性) 및 정량적(定量的) 차이가 있음을 알수 있었다. 혈청학적(血淸學的) 반응력(反應力)과 특이성(特異性)이 비교적 높은 항원성분(抗原成分)을 동정(同定)하기 위해 그러한 항원들이 비교적 많이 함유된 AFG7을 선택하였다. 전기영동(電氣泳動)으로 분리하여 nitrocellulose paper로 전이흡착(轉移吸着)시켜 A. fumigatus나 기타 진균항원(眞菌抗原)에 양성침강항체(陽性沈降抗體)(면역확산시험(免疫擴散試驗)에서)를 가진 혈청과 반응시킨 결과 적어도 36개의 항원성분이 검출되었다. 그러나 혈청학적 진단가치가 있는 항원성분은 4개 정도에 불과했다. 특이성과 반응력이 가장 높아 표준항원(標準抗原)에 반드시 함유되어야 할 것으로 보는 항원성분은 분자량(分子量)이 82 KD 정도되는 항원이었고 그 외에 11 KD, 26 KD, 30 KD 및 31 KD 등도 우수한 항원성분으로서 앞으로 더 연구검토되어야 할 것으로 본다. 반응력이 큰 항원이면 Coomassie청(靑)에는 흐리게 염색되어도 immunoblots상에는 짙게 염색되는데 비해 반응력이 약한 항원은 그와 반대현상을 나타내어 immunoblotting 분석법이 항원의 반응력과 특이성 관찰에 매우 유용함을 알 수 있다. 많은 항원성분이 균종특이(菌種特異) 항원결정기(抗原決定基)와 함께 광범한 균군(菌群)에 분포하는 항원결정기(抗原決定基)도 가지고 있었다.