• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.12-19
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• 2009

The aim of this study is to assess the antibiotic activity of Actinomyces in plaque from black stained primary teeth to Streptococcus mutans. Samples were obtained from four children, 2-6 years of age, who had black stains on all erupted primary teeth. 16 different Actinomyces spp. were isolated, and antibiotic activity test with paper disc method was done. The results were as follows, 1. No.1 and No.5 Actinomyces spp. showed the antibiotic activity to Streptococcus mutans and the activity of No.5 Actinomyces spp. could compete with that of Oxacillin. 2. No.1 and No.5 Actinomyces spp. also exhibited the antibiotic activity to Bacillus cereus, Bacillus subtilis commonly used as experimental bacteria for testing antibiotic activity. 3. For identification of No.1 and No.5 spp., PCR analysis was done. No.5 spp. matched Actinomyces viscosus at 97% level but No.1 spp. didn't match.

• Journal of Plant Biology
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• v.1 no.1
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• pp.3-10
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• 1958

Streptomycin 은 아직까지 가장 동물체에 안전한 항생물질로 알려져 왔으나, BROWNLEE와 BUSHBY (1948)에 의하면 백혈구가 Streptomycin 처리에 의해 죽는다고 하였다. 본인등은 Streptomycin을 처리한 흰쥐의 백혈구수의 변화와 백혈구 지체의 운동능에 미치는 영향을 조사하였다. 치사를 이르키게하는 최저를 이내인 10mg, 5mg, 2mg. 1mg. 0,5mg을 각각 흰쥐에 주사한 후 일정한 시간내의 백혈구수의 변화를 보면 처리후 1시간에서부터 6시간 사이에 백혈구수가 급격히 감소하며 정상지인 12,000에서 최하 3,000수까지 내려간다. 감소하는 정도는 처리량의 다소에 관계없이 대개동일하게 일어나는 것이다. 감소하는 원인을 추구하고저 쥐의 미부로부터 탐혈하여 이에 Streptomycin을 직접 접촉시켜 백혈구의 운동능을 조사하였다. Streptomycin의 량에 tt례하여 백혈구의 운동속도는 저하한다. 일정량을 초과할 때는 백혈구는 단시간내에 죽는다. 처리량의 다소를 불문하고 일정한 정도로 수의 감소가 일어나는 것과는 달리 백혈구의 운동능은 량에 따라 많은 변화를 가져온다. 이것으로 보아 백혈구수의 감소와 운동능의 저하와는 특별한 관계가 없는 것으로 보며 백혈구수 감소의 원인에 대해서는 추후 실험에서 밝혀야 할 것이다.

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.36-43
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• 1989

Out of 826 isolates of Streptomyces isolated from different soils, their distribution and antibiotic productivity were investigated. Distribution of the organism in the soil was affected by the soil conditions and plants. The highest isolation frequency was occurred from Quercus forest, Robinia forest and grass field, while soils from orchards and cultivating fields showed low density of Streptomyces. More than 49% of the isolates showed antibacterial activity against Bacillus subtilis, Erwinia carotovora subsp. carotovora and Xantomonas campestris pv. oryzae and about 40% of the isolates showed antiyeasty activity against Saccharomyces cerevisiae but only a few isolates showed antibiotic activity against E. coli and Pseudomonas solanacearum. Forty isolates of the Streptomyces showed strong antifungal activity against Pyricularia oryzae. Rate of isolation of Streptomyces was the highest on starch agar among the eight media tested. Antibiotic productivity of the isolates was the highest on potato sucrose agar medium among the 5 media tested.

• KOREAN POULTRY JOURNAL
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• v.43 no.7
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• pp.122-125
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• 2011

이번호에는 충남 연기군의 유일한 육용종계장으로 40년간 오로지 양계산업에 종사한 조은농장을 소개하고자 한다. 이곳은 다양한 효모제와 첨가제를 사용하면서 일체 항생제를 쓰지 않는 농장이다. 최근 추세가 무항생제를 선호하기 때문에 따라간다? 그렇지 않다! 조은농장 사장인 박순종 씨는 30년 전부터 이런저런 첨가제를 사용하면서 최소한 몇 년간 사육해보고 생산성에 효과가 있는 것으로 결과를 얻어 오로지 무항생제 축산업만을 고수하고 있다. 특히나 3년 전부터는 장기능 발달로 생체 활성화 효과가 있는 비타민 미네랄 활성화제제를 첨가 급이하면서 배부율이 크게 향상되는 등 높은 부화성적으로 농가 수익창출을 보고 있는 농장이다. 조은농장 박순종 사장을 만나 인터뷰한 내용을 정리했다.

• The Korean Journal of Food And Nutrition
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• v.23 no.1
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• pp.63-69
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• 2010

With the increase of the use of antibiotics and invasive procedures, infections caused by multidrug-resistant Acinetobacter baumannii(MRAB) are increasing. We screened the antibiotic producing strain B-51 for antibacterial activity against MRAB from the soils and studied the effects of culture medium on the antibiotic production of B-51. The medium conditions for maximum antibiotic productivity of B-51 was 2% glycerol, 0.5% soybean meal, 0.01% $CaCl_2$, 0.01% $MgSO_4{\cdot}7H_2O$ and 0.01% $KH_2PO_4$ at an initial pH of 6.0, at $30^{\circ}C$ for 76 h.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.103-109
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• 2009

In order to isolate antibiotic producing microorganisms, several actinomycetes were isolated from soil samples. The aerial hyphae of Y-88 strain were gray in color with tree types. Under the microscopic examination, the Y-88 isolate formed a spiral aerial spore mass with a smooth surface and a rectiflexibilis type of spore chain. Y-88 utilized glucose, fructose, arabinose, and sucrose, but not rhamnose, raffinose, mannitol, or inositol. In addition, Y-88 produced melanin on the tyrosine agar and the strain could utilize L-valine, L-phenylalanine, and L-hydroxyproline. Based on these results and the cultural and physiological characteristics described in the Bergey's Manual, the Actinomycetes, Y-88, was identificated as a Streptomyces species. The optimum medium conditions for this antibiotic producing Streptomyces sp. Y-88 was 1.6% soluble starch, 0.6% glucose, 0.6% beef extract, 0.01% $K_2HPO_4$, 0.01% $MgSO_4$ $7H_2O$, and 0.01% $ZnSO_4$ $7H_2O$ at an initial pH of 4.0, and 25$^{\circ}C$.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.40-47
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• 2005

In order to develop a multi-microbial biofungicide against several important plant pathogenic fungi, strains were isolated from the phtophthora blight suppressive red-pepper field soil of Gyeongsangbuk-do, Korea. Strains AY1, AY6, AB1, BB2 and F4, which had strong antagonistic ability against Phytophthota capsici and Fusarium oxysporum, were selected for their involvement with strains of biocontrol fungicide. There were no antagonism among the selected strains and were compatible for making the biofungicide. Their antagonistic mechanisms, except for strain BB2, were an antibiosis by the production of antibiotic, while BB2 produced not only an antibiotic but also cellulase as an antagonistic mechanism against blight causing P. capsici. They were identified as Halobacterium sp. AB1, Xenorhadus sp. AY1, Bacillus sp. AY6, Bacillus sp. BB2, Zymomonas sp. F4 by various cultural, biochemical test and $Biolog^{TM}$ System 4.0. The highest levels of antifungal antibiotic could be produced after 48 hrs of incubation under the optimal medium which were 0.1% galactose, 0.1% $NaNO_2$, 5 mM $Na_2{\cdot}HPO_4$ (pH 5.5). The cultured multi-microbial biofungicide showed strong biocontrol activity against bacterial wilt disease and fusarium wilt disease in cucumber and tomato fields.

• Journal of Applied Biological Chemistry
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• v.52 no.3
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• pp.116-120
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• 2009

We found out the new method of the consortium for the environmental friendly agriculture by 8 kinds of the selected antagonistic rhizobacteria. This research involved composition of mutual complementary consortium by each antagonistic function such as production of antibiotic, siderophore, antifungal cellulase and insoluble phosphate solubilization. The consortium No.11 among composed consortium candidates showed the most pepper growth promoting activity and Phytophthora blight suppression on the in vivo pot test of red-pepper plant. The consortium No. 11 is combination of PGPR Bacillus subtilis AH18 and Bacillus licheniformis K11. B. subtilis AH18 and B. licheniformis K11 both could produce the auxin, antifungal ${\beta}$-glucannase and siderophore. Also, they had mechanism for solubilization of insoluble phosphate. But, B. licheniformis K11 could produce the antibiotic of iturin which was able to inhibit Phytophthora capsici. We confirmed complementary noncompetitive mutualism between B. subtilis AH18 and B. licheniformis K11 of the consortium No.11. The results came out through treatment of two strains co-culture, treatment of individual culture and co-treatment of two individual cultures for the growth and Phytophthora blight suppression of red-pepper. The treatment of two strains co-culture didn't show a synergic effect in comparing sole treatment on the pepper growth promotion and Phytophthora blight suppression. But, when the pots were treated simultaneously with co-treatment of two individual cultures, an synergic effect was seen in the growth promotion of roots, stem, leaves and suppressed Phytophthora blight on red-pepper in vivo pot test.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.235-241
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• 2003

For the biological control of Phytophthora blight of red-pepper caused by Phytophthora capsici, an antibiotic-producing plant growth promoting rhizobacteria (PGPR) Bacillus sp. KL 39 was selected from a local soil of Kyongbuk, Korea. The strain KL 39 was identified as Bacillus megaterium by various cultural, biochemical test and API and Microlog system. B. megaterium KL 39 could produce the highest antifungal antibiotic after 40 h of incubation under the optimal medium which was 0.4% fructose, 0.3% yeast extract, and 5 mM KCl at 30 C with initial pH 8.0. The antifungal antibiotic KL 39 was purified by Diaion HP-20 column, silica gel column, Sephadex LH-20 column, and HPLC. Its RF value was confirmed 0.32 by thin-layer chromatography with Ethanol:Ammonia:Water = 8:1:1. The crude antibiotic KL39 was active against a broad range of plant pathogenic fungi, Rhizoctonia solani, Pyricularia oryzae, Monilinia fructicola, Botrytis cinenea, Alteranria kikuchiana, Fusarium oxysporum and Fusarium solani. The purified antifungal antibiotic KL39 had a powerful biocontrol activity against red-pepper phytophthora blight disease with in vivo pot test as well as the strain B. megaterium KL 39.

• Korean Journal of Microbiology
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• v.33 no.2
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• pp.111-117
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• 1997

Streptomyces virginiae produces a set of autoregulators termed virginiae butanolide A-E(VB-A-E) which trigger virginiamycin production, and possesses a high-affinity virginiae butanolide receptor. To elucidate the functions of VB-C and VB-C receptor, we isolated two mutants from S. virginiae by N-methyl-N'-nitro-N-nitrosoguanidine and hydroxylamine. The characteristics of the mutants showed that the producing time of antibiotics was very delayed due to a slower production of VB-C receptor than that of VB. In S. ostreogriseus(VB', receptor -) and S. graminofaciens(VBU, receptor+), which produce the virginiamycin, the addition of synthetic VB-C repressed the production of antibiotics in S. ostreogriseus but induced tbe production in S. graminofaciens. HPLC analysis of S. graminofaciens suggested that the VB-C might have an ability to induce the production of virginiamycin and other antibiotics. These results imply that the VB-C has an ability to trigger the production of other secondary metabolites as well as virginiamycin under VB-C receptor existence.