• The Korean Journal of Food & Health Convergence
• /
• v.9 no.6
• /
• pp.1-7
• /
• 2023

Secondary metabolites in the culture filtrates of lactic acid bacteria offer varied chiral moieties, making them a valuable resource for drug design scaffolding. Our previous methodology included using a combination of anion exchange resins, Amberlite IRA-67 and Purolite A420S, to purify significant quantities of Lactobacillus plantarum LBP-K10 peptidyl compounds. However, current experimental evidence regarding the impact of native culture extracts and/or filtrates on pathogenic fungi in vivo/in vitro is insufficient. This study analyzed the antifungal properties of two different probiotic cultures: the CH₂Cl₂-extracted filtrate of Chinese cabbage kimchi (CH₂Cl₂-extracted CCK_WLB and CH₂Cl₂-extracted CCK_WOLB) and the non-extracted filtrate of Chinese cabbage kimchi (non-extracted CCK_WLB and non-extracted CCK_WOLB). The samples were divided into two groups: one group was inoculated with probiotics while the other group remained non-inoculated. Filtrates from both experimental groups were utilized for antifungal assays. The treatments employing CCK_WLB, with an initial inoculation of Lb. plantarum LBP-K10 as a starter, demonstrated significant antifungal activity under various experimental conditions. Our study offers new perspectives on the antifungal properties of CH₂Cl₂-extracted kimchi filtrates, which are naturally produced by lactobacilli. The efficacy of antifungal compounds is supported by substantial evidence demonstrating their efficient uptake by cells and the antifungal properties exerted by metabolites.

• Applied Biological Chemistry
• /
• v.42 no.3
• /
• pp.181-187
• /
• 1999

For the selection of an effective antagonistic biocontrol agent, we have isolated an antagonistic bacterium which produced extracellular chitinase, from a local soil of Kyongju, Korea. The selected strain was identified as Serratia proteamaculans 3095. The chitinase produced from Serratia sp. 3095 showed antifungal activity which can attack the hypha surface of Fusarium oxysporum and F. solani. The carbon and nitrogen sources for chitinase production were 0.15% colloidal chitin and 0.1% ammonium sulfate, respectively. Glucose in the chitinase production medium might inhibit the production of chitinase by feed back repression. The antagonistic Serratia sp. 3095 also showed a powerful biocontrol activity against F. oxysporum through in vitro test and in vivo pot test.

• The Plant Pathology Journal
• /
• v.26 no.4
• /
• pp.360-366
• /
• 2010

In the course of a searhing environmental friendly antifungal compounds, we found that mixture of methyl esters of fatty acids obtained from soybean oil had potent control efficacy against barley powdery mildew (Blumeria graminis f. sp. hordei). In this study, ten alkyl fatty acid esters (AFAEs) were tested for in vivo antifungal activity against five plant diseases such as rice blast, rice sheath blight, tomato gray mold, tomato late blight and barley powdery mildew. Some AFAEs showed the most control efficacy against barley powdery mildew among the tested plant diseases. By 5-hr protective and 1-day curative applications, six AFAEs ($3,000\;{\mu}g/ml$), including methyl and ethyl palmitates, methyl and ethyl oleates, methyl linoleate, and methyl linolenate demonstrated both curative and protective activities against barley powdery mildew. In contrary, methyl laurate strongly controlled the development of powdery mildew on barley plants by curative treatment at a concentration of $333\;{\mu}g/ml$, but did not show protective activity even at $3,000\;{\mu}g/ml$. Under greenhouse conditions, the seven AFAEs ($1,000\;{\mu}g/ml$) except for methyl and ethyl stearates, and methyl caprylate also effectively controlled cucumber powdery mildew caused by Podosphaera xanthii. Among them, methyl and ethyl palmitates ($333\;{\mu}g/ml$) represented the most control activity of more than 68% against the disease. The results are the first report on the antifungal activity of methyl and ethyl esters of fatty acids against plant pathogenic fungi.

• Microbiology and Biotechnology Letters
• /
• v.32 no.4
• /
• pp.312-316
• /
• 2004

In oder to select the powerful rhizophere-dorminatable biocontrol agent, we had isolated an indigenous antagonistic bacterium which produced antibiotic and siderophore from a disease suppressive local field soil of Gyungsan, Korea. And we could select the Pseudomosp. 4059 which can strongly antagonize against Fusarium oxysporum and Phytophthora capsici by two kinds of antifungal mechanism that can be caused by the antibiotic of Phenazin, a siderophore and a auxin like subThe selected strain was identified as Pseudomonas fluorescens (biotype A) 4059 by biochemical tests, API $\textregistered$ test, MicroLog TM system and 16S rDNA analysis. The selected antagonistic microorganism, Pseudomosp. 4059 had an antifungal mechanism of antifungal antibiotic and sidrophore. And we were confirmed the antagonistic activity of P fluorescens 4059 with in vitro antifungal test against Phytophthora capsici and in vivo by red-pepper.

• The Plant Pathology Journal
• /
• v.18 no.2
• /
• pp.102-105
• /
• 2002

A strain of Acremonium strictum, the mycoparasite of Botrytis cinerea, showed strong antifungal activities both in vitro and in vivo against several phytopathogenic fungi. An antifungal substance was purified from the liquid cultures of A. strictum and identified as verlamelin by instrumental analyses. Verlamelin exhibited in vitro antifungal activity against some phytopathogenic fungi such as Magnaporthe grisea, Bipolaris maydis, and Botrytis cinerea, while it was net active against all the bacteria tested. In viva, verlamelin exhibited strong protective and curative activities, particularly against barley powdery mildew. At 100 μg/ml, it inhibited the development of barley powdery mildew with control values of more than 90% in 7-day protective and 2-day curative applications. This is the first report on the production of verlamelin by Acremonium species.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.95.2-96
• /
• 2003

In order to develop a new microbial fungicide for the control of vegetable diseases using endophytic bacteria, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth media, their antifungal activities were screened by in vivo bioassays against Botrytis cinerea(tomato gray mold), Pythium ultimum(cucumber damping-off), Phytopkhora infestans(tomato late blight), Colletotrichum orbiculare(cucumber anthracnose), and Blumeria graminis f. sp. hordei(barley powdery mildew). As the results of screening, 38 bacterial strains showed potent antifungal activities against at least one of 5 plant pathogens. A bacterial strain EB072 displayed potent disease control activities against 3 plant diseases. Among the bacterial strains with a potent antifungal activity against cucunlber anthracnose, three bacterial strains, EB054, EB151 and EB215, also displayed a potent in vitro antifungal activity against C. acutatum, a fungal agent causing pepper anthracnose. A bacterial strain EB215 obtained from roots of cucumber was identified as Burkholderia cepacia based on its physiological and biochemical characteristics and 165 rRNA gene sequence. An antifungal substance was isolated from the liquid cultures of B. cepacia EB215 strain by ethyl acetate partitioning, repeated silica gel column chromatography, and invitro bioassay, Its structural determination is in progress by various instrumental analyses.

• Preventive Nutrition and Food Science
• /
• v.22 no.2
• /
• pp.138-143
• /
• 2017

The antifungal activity of isolated lactic acid bacteria (LAB) from a locally fermented cereal, "Kunu", was tested against toxigenic Aspergillus flavus. The liquid refreshment, "Kunu", was prepared under hygienic condition using millet, sorghum, and the combination of the two grains. The antifungal potential of isolated LAB against toxigenic A. flavus was carried out using both in vitro and in vivo antifungal assays. The LAB count from prepared "Kunu" ranged from $2.80{\times}10^4CFU/mL$ to $4.10{\times}10^4CFU/mL$ and Lactobacillus plantarum, Lactobacillus delbrueckii, Lactobacillus fermentum, Pediococcus acidilactici, and Leuconostoc mesenteroides were the isolated bacteria. Inhibitory zones exhibited by LAB against toxigenic A. flavus ranged from 5.0 mm to 20.0 mm. The albino mice infected with toxigenic A. flavus showed sluggishness, decrease in body weight, distortion of hair, and presence of blood in their stool, while those treated with LAB after infection were recovered and active like those in control groups. Except for the white blood cell that was increased in the infected mice as $6.73mm^3$, the packed cell volume, hemoglobin, and red blood cell in infected animals were significantly reduced (P<0.05) to 29.28%, 10.06%, and 4.28%, respectively, when compared to the treated mice with LAB and control groups. The antifungal activity of LAB against toxigenic A. flavus can be attributed to the antimicrobial metabolites. These metabolites can be extracted and used as biopreservatives in food products to substitute the use of chemical preservatives that is not appealing to consumers due to several side effects.

• Research in Plant Disease
• /
• v.17 no.2
• /
• pp.155-160
• /
• 2011

To develop the efficient screening methods for antifungal compound active to Chinese cabbage clubroot caused by Plasmodiophora brassicae, the control efficacy of three fungicides fluazinam, ethaboxam, and cyazofamid on the disease was tested under several conditions such as soil types, cultivars of Chinese cabbage, growth stages of the host, and inoculum concentrations. The in vivo antifungal activities of the fungicides on clubroot of two Chinese cabbage cultivars were hardly different. At 7- and 14-day-old seedlings, the fungicides were more effective to control of clubroot than at 21-day-old seedlings. In a commercial horticulture media soil (CNS), disease severity of untreated controls was higher and control activity of the fungicides was less than in a mixture of CNS and upland soil (1:1, v/v). Disease development of the seedlings inoculated with P. brassicae at $1.8{\times}10^7$ spores/pot to $1.1{\times}10^9$ spores/pot was almost same, but control efficacy of the fungicides was negatively correlated with inoculum dosages. To effectively select in vivo antifungal compound on Chinese cabbage clubroot, 14-day-old seedlings need to be inoculated with P. brassicae by drenching the spore suspension to give $1{\times}10^8$ spores/pot 1 day after chemical treatment. To develop clubroot, the inoculated plants are incubated in a growth chamber at $20^{\circ}C$ for 2 days, and then cultivated in a greenhouse ($20{\pm}5^{\circ}$) for four weeks.

• The Korean Journal of Pesticide Science
• /
• v.8 no.1
• /
• pp.8-15
• /
• 2004

A synthesis of new $\beta$-ketoacetoanilide chloride derivatives and anti fungal activity of these compounds library against 6 typical plant pathogens were described. Reaction of ketene dimer with chlorine followed by treatment of aniline derivatives gave 89 kinds of the corresponding $\beta$-ketoacetoanilide chlorides through combinatorial synthetic technology using Carousel Reaction Stations. Evaluation of antifungal activity (in vivo) of this chemical library against rice blast, rice sheath blight, tomato aray mold, tomato late blight, wheat leaf rust and barley powdery mildew was carried out. In general, $\beta$-ketoacetoanilide chlorides which present a substituent at 4 in phenyl group(para) of the compounds showed selective control activity against tomato late blight caused by Phytophthora infestans.

• Korean Journal of Medicinal Crop Science
• /
• v.6 no.4
• /
• pp.277-285
• /
• 1998

Antifungal activity on major seedborne diasease of crops was screened by the treatment of the extracts from 50 medicinal plants in vitro and in vivo. The extracts of garlic and taxus, Rheum undulatum, Achiranthes japonica, Glycyrrhiza uralensis, Oenothera lamar kiana treated with the blotting filter paper and water agar methods inhibited the growth of Pyricularia oryzae, Alternaria sesamicola, Colletotrichum gloeosporioides, and Alternaria brassicicola among the tested plants. Antifungal activities on infected seeds by soaking methods were shown even at the dilution of the extracts by 10 times. The activity was the highest in soaking seeds at $25^{\circ}C$ for 24 hours. The effect of plant extract on seed germination was not significant as compared with untreated seed. However, early growth of seedling was increased by the treatment of extracts. The extract of taxus slightly inhibited the seed germination of radish and chinese cabbage but those of Achirunthes japonica, Glycyrrhiza uralensis and Oenthfera lamarkiana showed severe damage on the seed germination and early growth of seedling.