• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.53-60
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• 1984

The followings are the results obtained from the investigation of isolation and cultural conditions of a fungus producing antibiotic from humus, spring soil, paddy, field and etc. 1. Among fungi which were capable of antimicrobial sub stance producing at the $45^{\circ}C$, Strain H-3 was selected as test st rain because of its efficiency in antimicrobial substance producing. 2. Strain H-3 was identified as a Aspergullus fumigatus by the mophological properties. 3. The compositions of optimun media for the production of antimicrobial substance were followed;glucose 20g, $NaNO_3$ 3g, $K_2HPO_4$ 1g, $CaCl_2$ 0.5g, $MgSo_4$ 0.5g, $FeSO_4$ 0.005g. 4. Optimum culture conditions were founded to be pH 5.0, $40^{\circ}C$ respectively. 5. The maximum antimicrobial substance producing obtained in this study was showed 14mm of clear zone after 72 hrs incubation under the optimum conditions. 6. AF-c substance was active against Gram-positive, Gram-negative bacteria, and yeast but not mold in its biological properties.

• The Korean Journal of Pesticide Science
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• v.3 no.2
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• pp.1-7
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• 1999

The strain with antibacterial activity was isolated among soil samples collected in Suwon area. The isolated strain was identified as Bacillus sp. YR-1 with respect to its morphological, cultural, and physiological characteristics. Optimal medium for the highest production of antibiotic was composed of sucrose 2.0%(w/v), peptone 2.0%(w/v) and NaCl 0.1%(w/v). The maximum production of antibiotic was shown at $35^{\circ}C$ for 48 hours with the initial pH 7.0.

• Microbiology and Biotechnology Letters
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• v.10 no.1
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• pp.39-43
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• 1982

t-Cinnamamide has been isolated from the culture filtrate of the isolates, Streptomyces. sp. No.297 The identity of the compound was established by UV and IR spectra, NMR, mass spectra and by chemical reactions. Through antimicrobial activity test using a two-fold serial agar dilution mothjod, t-cinnamamide showed strong growth inhibitory activity against Pellicularia sasakii, Pyriculario oryzae and some pathogenic fungi, but not inhibitory over procaryotes tested.

• 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.

• Microbiology and Biotechnology Letters
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• v.17 no.3
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• pp.247-251
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• 1989

Effects of mineral salts on sisomicin fermentation were investigated. The optimal concentration of CoCl$_2$for accomplishing a high antibiotic yield was found to be 16.8 $\mu$M at which it could function as a cofactor. At this level the other mineral salts tested had no effect. On the other hand, at much higher concentration levels (above 1 mM), four mineral salts such as ZnSO$_4$, KH$_2$PO$_4$, FeSO$_4$and MgSO$_4$were used in order to liberate the intracellular sisomicin out-side the cells, because the sisomicin accumulated mostly in cells and it was supposed to limit the improvement of antibiotic yield. ZnSO$_4$and KH$_2$PO$_4$had no effect at all, and FeSO$_4$brought about some improvement. However, by keeping the concentration of MgSO$_4$to be 25 mM or higher in culture broths, the antibiotic yield could be improved by more than 100%, partially due to the enhanced liberation of the intracellular antibiotic.

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.52-56
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• 1984

In order to evaluate the applicability of two kinds of antibiotic fermentation residues on rice and tomato growth, yield, yield components, and some indicators for plant growing status were checked including analysis of physico-chemical properties of these two antibiotic fermentation residues. The results obtained are as follows: 1) These two antibiotic fermentation residues contain high organic matter ($21.6{\sim}24.2%$), phosphorus ($2900{\sim}4600 ppm$) and exchangeable cations ($55.4{\sim}138.3 meq/100 g$,), showing their pH values of $7.0{\sim}8.0$ range. 2) Both have developed net positive charge rather high and stiffly that exhibits high negative ion adsorption capacities, accordingly showing higher zero point of charges($pH 7.0{\sim}8.0$) than those of common soils. 3) The effect of the two kinds of antibiotic fermentation residues on rice growth was more or less the same comparable to the effect of the other fertilizers applied, showing the maximum yield at the application rate of 40 ㎏/10a. 4) The effect of these antibiotic fermentation residues on tomato growth was also similar to effects on rice plant showing the yield increment upon fertilizer application including two antibiotic fermentation residues but no significant differences among fertilizers. 5) According to the plant growing status, plant height, dry matter, number of effective tillers and grain number per panicle of rice and plant height and fresh weight of plant of tomato showed similar trend with yield of both plants.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.98.4-98
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• 1978

방선균에서 RNA 분해효소력이 강한 균주를 토양으로부터 선별하여 이 균주의 RNA 분해산물을 검토하고 부산물로서 항생물질의 생성을 조사하였다. 먼저 동시 생성 생육조건을 검토한 결과, 유기 질소원으로서 soybean meal 1.5%, 무기 질소원으로서는 $KNO_3$ 0.05% 첨가하였을 때 효과가 있었고, 탄소원으로서는 가용성 전분 2% 첨가시가 조건이 좋았다. 무기염류를 배지에 첨가하였을 때 별 다른 영향이 없었고 오히려 $CuSO_4를$ 가하였을 때는 저해를 보였다. 최초 pH가 7.0, 배양 2일째에 균체증식, 효소생산 및 항생물질의 생산이 최대를 나타내었다.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.11a
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• pp.19-25
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• 1997

Bicyclomycin(BCM)은 1972년에 일본 Hokkaido, Sapporo지방의 토양균중의 하나인 Streptomyces Sapporoneosis의 배양액으로부터 최초로 분리된 항생물질로서 특히 Gram(-) 박테리아인 Escherichia coli. Klebsiella, Shigella, Salmonella, Citrobacter, Enterobacter cloacae, Neisseria gonorrhoeae등에 대한 선택적인 항균효과를 가지고 있고 Streptomycin, Kanamycin, Chloramphenicol, Tetracyclin, Aminobenzylpenicillin 및 naldixic acid 등에 대해 교차내성을 가지고 있지 않다. BCM은 구조적인 면에서 [4.2.2]bicyclic구조를 가지고있는 특이한 항생물질로서 C(1)-triol부분, diketopiperazine부분 그리고 C(5)-C(5a)exomethylene의 3 부분으로 크게 나눌수 있다(Fig. 1). BGM은 E. coli에 대한 항균력으로서 250-500 $\mu\textrm{g}$/mL의 MIC value를 가지고 있고 급성독성으로서 LD$_{50}$가 4g/kg 이상으로 거의 독성이 없는 것이 특징이다. 현재 Fujisawa pharmaceutical Ltd.로부터 Bicozamycin이라는 상품명으로 설사치료제 용도로 시판되고 있다.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.604-609
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• 1991

Antibiotic MT-497 was purified from the culture broth of Streptomyces nigr$^1H-NMR$ and composition of amino acids, MT-497 was identified as one of the actinornycin antibiotics containing actinocin chromophore and the peptide with threonine, proline, methyl valine, sarcosine and aspartic acid.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.213-218
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• 1992

Fermentation patterns were changed by adding magnesium sulfate to the fermentation broth and its effect on enhancement of sisomicin production was investigated. When cell growth was expressed by DNA content, trophophase and idiophase were separated, but not by dry cell weight. On the other hand, addition of magnesium sulfate had the antibiotic accumulated inside the cells be liberated into the outside, and this effect resulted in improving the final antibiotic yield. The maximum antibrotic yield was obtained when 100 mM magnesium sulfate was added after one day of cultivation, and enhanced more than three times compared to that of the control to which it was not added.