• Mycobiology
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• v.29 no.4
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• pp.210-217
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• 2001

Seventy-three species and five varieties belonging to 36 genera were collected from leaf surfaces of banana plants on glucose and cellulose-Czapek's agar at $28^{\circ}C$. The results obtained from leaf surfaces(phyllosphere and phylloplane) were basically similar on the two types of media and the most common fungi were Alternaria, Aspergillus, Chaetomium, Cladosporium, Cochliobolus, Curvularia, Gibberella, Memnoniella, Mycosphaerella, Setosphaeria and Stachybotrys. The monthly counts of these fungi were irregularly fluctuated giving maxima at various months. Chaetomium globosum was in the top of fungi in producing both exo- and endo-$\beta$-l,4-glucanases among the 34 tested isolates obtained from leaves(phylloplane) on cellulose-Czapek's agar. Maximum production of these enzymes by C. globosum was 6 and 8 days after incubation at $25^{\circ}C$ with culture medium containing wheat bran as a carbon source and peptone as a nitrogen source and initially adjusted to pH 6.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.159-165
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• 1997

We collected 3,237 plant samples, mainly leaves of various trees, from many provinces in Korea and a total of 1,925 Bacillus thuringiensis isolates were obtained and characterized. The isolates were characterized in terms of crystal morphology, PAGE pattern of the toxin proteins, plasmids pattern, biochemical characteristics, and bioassay. The microscopic observation showed that 49.1% of the isolates have bipyramidal shape crystals, 7.1% of spherical shape crystals, 1.4% of rhomboidal shape crystals, and others have small or amorphous inclusions. The insecticidal activities of the spore-crystal mixtures of isolates were tested against Plutella xylostella, Bombyx mori, Culex pipiens, and Agelastica coerulea. Bioassay showed that 51.3% of the isolates were shown to be active; lepidopteran-specific (44.8%), dipteran-specific(4.9%) and coleopteran-specific (1.6%). The remainder(48.8%) did not show any activity against the insects we tested. Interestingly though, some of these non-active isolates were shown to have bipyramidal crystals. By serotyping 22 isolates of our collection, we found that there are various kind of subspecies such as aizawai, amagiens, canadensis, darmstadiensis, galleriae, finitimus, kurstaki, morrisoni and neoleonensis, and three isolates have been classified into a new serotype, H49, and one of them, the type strain, named subsp. muju. From this study it was found that phylloplane is a good source for the isolation of Bacillius thuringiensis, and Bacillus thuringiensis is distributed widely in Korea.

• The Plant Pathology Journal
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• v.15 no.3
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• pp.162-167
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• 1999

Integration of microbial antagonists with fungicides was tried to control the gray mold caused by Botrytis cinerea on pepper in greenhouse conditions and to reduce fungicide uses. All of the selected bacterial antagonists, Bacillus amyloliquefaciens BL3, Paenibacillus polymyxa BL4, and Pseudomonas putida Cha94, completely inhibited the conidial germination of B. cinerea until 30 days after treatment. However, bacterial colonization of pepper phylloplane was poor in BL4, while the other bacterial isolates and the fungal antagonist Trichoderma harzianum TM colonized well on the phylloplane, maintaining the population density of 104-105 cfu/g until 15 days after microbial treatments. Out of 13 kinds of selected fungicides used for gray mold diseases, polyoxin B and BKF 1995 showed the most discriminatory activity on the fungal growth between B. cinerea and TM. TM grew readily on the media containing those fungicides, while B. cinerea showed poor or no mycelial growth on them. The selected fungicides and antagonists alone reduced incidence of gray mold on pepper, showing disease indices of about 2.4 to 3.0, while its was increased up to 4.2 in the untreated control. Alternate treatments with the antagonists and 2-fold diluted fungicides inhibited the disease incidence as much as the antagonists or fungicides alone, and reduced the secondary inoculum more than the single treatments. This suggests that integration of antagonists and fungicides may be an efficient way to reduce fungicide sprays with reliable control efficacy of the disease. However, there was not much difference in the early and mid-term disease progress among the treatments and the untreated control, probably due to extremely favorable environmental conditions for the disease development in this experiment.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.98.1-98
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• 2003

Antagonistic effect of bacterial strains isolated from phylloplane of strawberry plants grown In greenhouse was tested on Botrytis cinerea Among the promising bacterial strains, Bacillus sp. S1-0210 showed highest inhibition of mycelial growth of B. cinerea and a broad spectrum of antifungal activities against many plant pathogenic fungi in vitro. Bacillus sp. S1-0210 was identified as Bacillus subtilis based on the analysis of 185 rDNA as well as its biochemical characteristics. Application of wettable powder formulation of B. subtiiis S1-0210 significantly reduced the incidence of gray mold on trawberry fruits during storage. Results showed that treatment of B. subtilis S1-0210 decreased the incidence of gray mold by 4.8％ whereas the incidence in control was 77.9％, indicating that the formulation of B. subtilis S1-0210 will be practically applied on strawberry fruits as a biocontrol agent of gray mold during storage.

• Microbiology and Biotechnology Letters
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• v.25 no.5
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• pp.454-458
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• 1997

To develop a yellow pigment for a food-additive, a strain producing a water-soluble yellow pigment was isolated from phylloplane of tree leaf. The strain PY123 was identified a Bacillus sp. based on morphological and biochemical characterization such as a bacillus form, mortility, spore formation, Gram positive, and catalase production. The pigment production of the strain PY123 was increased about 3 times in patato broth containing 1% sucrose and 0.1 mM CoCl$_{2}$ than in only potato broth after incubation at 30$circ$C, for 2 days. When 0.1 mM CoCl$_{2}$, was added in potato broth containing 1% sucrose at late log phase during incubation of the strain PY123, cell growth was not inhibited, and the period at maximal pigment production of the strain PY123 was about 12hrs faster than in potato broth containing 1% sucrose and 0.1 mM CoCl$_{2}$, simultaniously.

• The Plant Pathology Journal
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• v.25 no.1
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• pp.99-102
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• 2009

An antagonistic bacterium of Bacillus subtilis BD0310 against Colletotrichum theae-sinensis was isolated from the phylloplane of tea trees at a tea plantation in Korea. SC (suspension concentrate)-type biofungicide was formulated with the antagonist. Cell viability and antifungal activity of B. subtilis were maintained in the formulation more than 12 months at room temperature. The antagonist was sensitive only to copper sulfate among the chemical pesticides currently registered for tea trees in Korea. Greenhouse application demonstrated that the biofungicide controlled more effectively the disease in a protective mode than in a curative mode. Field trial showed that alternate applications of the biofungicide and chemical fungicide were more effective in controlling tea anthracnose than single application of the biofungicide or chemical fungicide with less use of chemicals. This study suggests that the biofungicide of B. subtilis 8D0310 is an effective method for biological control of anthracnose in tea plantations.

• Journal of Microbiology and Biotechnology
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• v.28 no.9
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• pp.1511-1516
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• 2018

In this study, we investigated Indole-3-acetic acid (IAA) production by a rice phylloplane bacteria, Enterobacter sp. DMKU-RP206, using sweet whey as a feed stock instead of lactose. We succeeded in using sweet whey for Enterobacter sp. DMKU-RP206 to produce 3,963.0 mg IAA/l with the optimal medium containing 1.48% sweet whey, 1.42% yeast extract and 0.88% $\text\tiny{L}$-tryptophan. The medium pH was adjusted to 6 and the culture conditions were shaking at 200 rpm on an orbital shaker at $30^{\circ}C$ for 3 days. We also evaluated the effect of IAA in culture filtrates of Enterobacter sp. DMKU-RP206 on the promotion of jasmine rice growth in a pot experiment. Compared with the negative control (without IAA), the result showed that biosynthetic IAA produced by Enterobacter sp. DMKU-RP206 significantly increased the growth of jasmine rice (Oryza sativa L. cv. KDML105) in terms of length and dry weight of shoot. This work thus reveals the impact of IAA produced by Enterobacter sp. on the promotion of jasmine rice growth.