• Research in Plant Disease
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• v.26 no.1
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• pp.8-18
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• 2020

Red pepper, one of the major economic crops in Korea, is being affected by anthracnose disease caused by Colletotrichum acutatum. To control this disease, an antagonistic bacterial strain, Bacillus subtilis YGB36 identified by 16S rDNA sequencing, physiological and biochemical analyses is used as a biological control agent. In vitro screening revealed that the strain YGB36 possess strong antifungal activity against the pathogen Cylindrocarpon destructans. The strain exhibited cellulase, protease, amylase, siderophore production and phosphate solubility. In vitro conidial germination of C. acutatum was most drastically inhibited by YGB36 cell suspensions (10⁶ cfu/ml) or culture filtrate. Development of anthracnose symptoms was reduced on detached immature green pepper fruits by treatment with cell suspensions, and its control value was recorded as 65.7%. The YGB36 bacterial suspension treatment enhanced the germination rate of red pepper seeds and promoted root development and growth under greenhouse conditions. The in vitro screening of fungicide and insecticide sensitivity test against YGB36 revealed that the bacterial growth was not affected by any of the insecticides, and 11 fungicides out of 21 used. Collectively, our results clearly suggest that the strain YGB36 is considered as one of the potential biocontrol agents against anthracnose disease in red pepper.

• Journal of Life Science
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• v.26 no.7
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• pp.796-804
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• 2016

In the present study, we screened suitable yeasts for wine fermentation and evaluated the fermentative characteristics of Saccharomyces sp. BCNU 6006 and its anti-oxidant activities. Firstly, various yeasts were isolated from Makgeolli, fruits, and fermented foods. Then, the preliminary selections of suitable yeasts were made using an enzymatic activity assay of glucosidase, glycosidase, protease and tolerance to ethanol and SO₂. In addition, the production of biogenic amines and hydrogen sulfide was also monitored. The 9 yeast strains initially selected were determined to belong to the genera Saccharomyces and Kazachtania phylogenetically. We investigated the optimal conditions for wine fermented with black garlic juice (BGJ). The optimal conditions of alcohol fermentation using BGJ were 26 brix, 28℃, and 10 days. Finally, the fermentation products of black garlic wine (BGW) fermented with Saccharomyces sp. BCNU 6006 exhibited 15.03% ethanol, 12 brix of sugar, and pH 4.01. The contents of total polyphenol, total flavonoid, tannin, and 5-HMF compound of BGW were 3.85 mg/ml, 0.51mg/ml, 5.90 mg/ml, and 0.07 mg/ml respectively, lower than that of BGJ. DPPH radical scavenging activity, ABTS radical scavenging activity, and reducing power of BGW were 90.77%, 95.20% and 1.261 respectively, lower than that of BGJ. Superoxide anion (O²-) radical scavenging activity was 94.42%, higher than that of BGJ. Based on the above results, the industrial potential of Saccharomyces sp. BCNU 6006 as a wine-making yeast was confirmed in the present study.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.11
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• pp.1661-1665
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• 2003

A feeding trial was conducted for 60 days to study the utilization of fruits processing wastes as feed ingredient in the diet of Labeo rohita fingerlings. One hundred and sixty fingerlings (av. body weight, $1.65g{\pm}0.03$) were equally distributed in four experimental groups having 4 replicates each. Four different experimental diets were prepared by replacing wheat flour and rice bran with either orange (T2) (Cirtus qurantium), pineapple (T3) (Ananas spp. and Pseudananas spp.) or sweet lime (T4) (Citrus sinensis) wastes to the basal diet along with the control (T1, without any fruit wastes) keeping the CP level at around 40%. The water quality parameters like DO, $CO_2$, pH, total alkalinity, total hardness, ammonia and water temperature were recorded within the optimum range. The diet containing 25% pineapple wastes (T3) showed significantly higher growth in terms of SGR (1.50), FCR (2.09) and PER (1.19) than the other groups. However, growth of T4 and T2 groups were not significantly different than the control group (T1). Protease activity (17.17 unit/mg protein), protein digestibility (91.57%) and carbohydrate digestibility (41.62%) were not significantly different among the different groups. Survival of the fingerlings were not significantly different among the experimental groups. It concludes that waste of orange, pineapple and sweet lime can be used at 25% level as a substitute of wheat flour and rice bran in the diet of Labeo rohita.

• The Korean Journal of Mycology
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• v.25 no.4 s.83
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• pp.320-329
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• 1997

Botrytis cinerea isolates obtained from infected plants of cucumber, tomato, and strawberry were divided into three groups (sporing, sclerotial, and mycelial types). Of which sclerotial types were the major group. There were no correlations between morphological phenotypes and responses to benzimidazole and dicarboximide fungicides. External structure of conidia of three phenotypes by scanning electron microscope was the same with verrucose surface. Mycelial type was the most virulent on fruits of eggplants. Comparative tests were carried out to examine correlations between the virulence and production of fungal enzymes such as phenol oxidases, pectin methyl esterases (PME), amylases, cellulases, ureases, ${\beta}-glucosidases$, and proteinases. There was no correlation among the phenotypes in production of phenol oxidases and ${\beta}-glucosidases$. However, there were significantly different from each other in PME, amylase, cellulase, urease, and protease activity.

• The Plant Pathology Journal
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• v.40 no.4
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• pp.346-357
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• 2024

This study was carried out to screen the antifungal activity against Colletotrichum acutatum, Colletotrichum dematium, and Colletotrichum coccodes. Bacterial isolate GP-P8 from pepper soil was found to be effective against the tested pathogens with an average inhibition rate of 70.7% in in vitro dual culture assays. 16S rRNA gene sequencing analysis result showed that the effective bacterial isolate as Bacillus siamensis. Biochemical characterization of GP-P8 was also performed. According to the results, protease and cellulose, siderophore production, phosphate solubilization, starch hydrolysis, and indole-3-acetic acid production were shown by the GP-P8. Using specific primers, genes involved in the production of antibiotics, such as iturin, fengycin, difficidin, bacilysin, bacillibactin, surfactin, macrolactin, and bacillaene were also detected in B. siamensis GP-P8. Identification and analysis of volatile organic compounds through solid phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) revealed that acetoin and 2,3-butanediol were produced by isolate GP-P8. In vivo tests showed that GP-P8 significantly reduced the anthracnose disease caused by C. acutatum, and enhanced the growth of pepper plant. Reverse transcription polymerase chain reaction analysis of pepper fruits revealed that GP-P8 treated pepper plants showed increased expression of immune genes such as CaPR1, CaPR4, CaNPR1, CaMAPK4, CaJA2, and CaERF53. These results strongly suggest that GP-P8 could be a promising biocontrol agent against pepper anthracnose disease and possibly a pepper plant growth-promoting agent.

• Journal of Life Science
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• v.12 no.6
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• pp.752-758
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• 2002

This study was investigated on properties and thermostability of gelatin-degrading proteinases in the fruit of Actinidia chinensis (kiwifruit) for the industrial application. Three gelatin-degrading proteinases (PI, PII and PIII) were detected from the pulp of fruits. The molecular weights of these proteinases, PI, PII and PIII, were approximately 220 kD, 51 kD, and 26 kD respectively, on the basis of gelatin-containing SDS-PACE. The optimum pH of these proteinases ranged from 2.0 to 5.0 with a maximal activity at pH 4.0. These proteinases had a high sensitivity to E-64 and iodoacetate which are cysteine protease inhibitors, and required DTT, cysteine, and $\beta$-mercaptoethanol for their activities which are stimulators for cysteine proteases. These results indicate that these proteinases are cysteine proteinases and the proteinase PIII is actinidin (EC 3.4.22.14), based on the molecular weight and/or susceptibility against proteinase inhibitors. These proteinases were strongly activated by $Ca^{2+}$, $Mg^{2+}$ and $Mn^{2+}$, whereas strongly inhibited by Zn$^{2＋}$ and Hg$^{2＋}$. However, these proteinases have slightly different susceptibility against other cations ($Ca^{2+}$, $Cu^{2+}$, $Al^{3+}$, $Ca^{3+}$. The temperature stability of proteinase PIII was more stable than proteinases PI and PII. Moreover, proteinase PIII remained stable below $50^{\circ}C$ for 48hr, showing the residual activity above 75% of the enzyme activity.

• Research in Plant Disease
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• v.29 no.4
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• pp.390-398
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• 2023

Apple white rot, caused by Botryosphaeria dothidea, is one of the important diseases in Korea. B. dothidea can cause pre- and postharvest decay on apple fruit as well as canker and dieback of apple trees. In this study, we isolated bacteria from the trunk of apple trees and tested their antagonistic activity against B. dothidea. Five bacterial isolates (23-168, 23-169, 23-170, 23-172, and 23-173) were selected that were most effective at inhibiting the mycelial growth of the pathogens. The isolate 23-172 was identified as Bacillus amyloliquefaciens and four isolates 23-168, 23-169, 23-170, and 23-173 were identified as Bacillus velezensis by RNA polymerase beta subunit (rpoB) and DNA gyraseA subunit (gyrA) gene sequencing. All isolates showed strong antagonistic activity against B. dothidiea as well as Colletotrichum fructicola and Diaporthe eres. All isolates exhibited cellulolytic, proteolytic and phosphate solubilizing activities. In particular, two isolates 23-168, 23-169 were shown to significantly reduce the size of white rot lesions in pretreated apple fruits. These results will provide the basis for the development of a fungicide alternative for the control of white rot of apple.