• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.483-488
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• 2011

Present work comprises of synthesis various analogues of ciprofloxacin by introducing new functionality at carboxylic group position via ester aminolysis reaction. For this purpose the carboxylic group at C-3 was esterified and later subjected to nucleophilic attack at the carbonyl carbon by various aromatic amines. Structure of the analogues was confirmed by different techniques i.e. IR, $^1H$ NMR and mass spectrometry. The antibacterial activity of the derivatives was also assessed with the parent against a series of Gram-positive and Gram-negative bacteria. The synthesized compounds showed diverse antimicrobial profile among which most compounds possessed a comparable or better activity in comparison to the ciprofloxacin. Additionally unlike ciprofloxacin, some of the derivatives were also found to show antifungal activity.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.74.2-74.2
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• 2007

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• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.5
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• pp.832-836
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• 2000

A bactirium prohibiting the growth of fungus Botrytis cineria KT 433 was isolate and identified from soil. The isolated strain was gram positive, aerobic bacteria with cream color, round and mucoid. It showed ord form of 0.45$\times$1.1 ${\mu}{\textrm}{m}$ at the cultivated for 24 hrs and the ellipsoided endospore wer observed after culting for 72 hrs. The optimum growth temperature and pH wer 35$^{\circ}C$ and pH 5.0~8.0, respectively. It could assimilate daxtrin, maltose, glucose, mannose, ribose and collobiose as a sole carbon source. The isolated was confirmed to be a Bacillus sp. strain from the findings. The antibiotic from the isolated strain was stable up to 121$^{\circ}C$. The strain, especially, showed specific activity for mold and yeast. However, there was not significant antibacterial activity.

• Applied Biological Chemistry
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• v.41 no.3
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• pp.208-212
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• 1998

In order to develop an effective antifungal antibiotics, over 700 isolates of bacteria, mold and actinomytes were screened from soil, and LAM 97-44 were selected as a strain producing the strong antifungal antibiotics against Candida albicans. Morphological, cultural and physiological characteristics of LAM 97-44 were investigated for the indentification. The cell size of LAM 97-44 was $2{\sim}3{\times}1{\sim}1.5\;{\mu}m$, and the shape of spore was of ellipsoidal. As a carbon source, LAM 97-44 utilized fructose, glucose, glycerol, maltose and raffinose but did not utilize arabinose, cellulose and xylose. The fatty acids of the cells included various iso-type and anteiso-type. Conclusively, the strain LAM 97-44 was proved to be Bacillus subtilis.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2313-2320
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• 2018

Tetramethylene-1,4-bis(N,N-dodecylammonium bromide), cationic gemini surfactant, (12-4-12) was first synthesized with an one-step and shortened procedure and its interfacial and antimicrobial properties were compared with a conventional single-chain cationic surfactant, cetyltrimethylammonium bromide (CTAB). The interfacial and thermodynamic properties of both surfactants reveal that critical micelle concentration (CMC) of this novel synthetic cationic dimeric surfactant is lower than that of cationic monomeric surfactant at almost 15 times of its magnitude, which is due to the increase in hydrophobicity of the surfactant molecules by having dual hydrocarbon chains. In comparison with CTAB, the produced compound 12-4-12 yields much better interfacial and thermodynamic properties. The antimicrobial activities of the synthesized gemini surfactant were tested against eight strains of bacteria, as well as two strains of fungi. The results showed that both 12-4-12 compound and CTAB exhibited higher inhibitory effects on the growth of Gram-positive bacteria and fungi than that of Gram-negative bacteria. The minimum inhibitory concentrations in molar of 12-4-12 against all tested Gram-negative bacteria were lower than those of CTAB, which is hypothetically due to the lower HLB together with smaller CMC values of our gemini surfactant.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.178-186
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• 2012

This study was investigated for the purpose of the isolation and identification of antagonistic bacteria with antifungal activity against plant pathogens. This bacteria denominated Bacillus subtilis KYS-10 and the optimum growth condition were 4% sucrose, 1% yeast extract, 0.2% $K_2HPO_4$, pH 7, 150 rpm, $30^{\circ}C$, 8 day. The antifungal activities against nine plant pathogens determined inhibition zone size by diffusion methods. The results, G. zeae (scab) 70 mm and P. grisea KACC 40439 (blast), P. capsici KACC 40177 (phytophthora blight) and C. destructans KACC 41077 (root rot of ginseng) 40~43 mm, and C. gloeosporioides KACC 43520 (ripe rot), C. gloesporioides KACC 40003 (anthracnose), S. shiraiana KACC 41065 (stem rot) and S. shiraiana (mulberry sclerotial disease) 35~39 mm and F. Oxysporum KACC 44452 (bulb rot of ginseng) 28 mm. From these experiment results, author suggest that Bacillus subtilis KYS-10 would be developed as a biological control agent thorough the field experimet in the near future.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.25-25
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• 2016

Biological control has many advantages as a disease control method, particularly when compared with pesticides. One of the most important benefits is that biological control is an environmental friendly method and does not introduce pollutants into the environment. Another great advantage of this method is its selectivity. Selectivity is the important factor regarding the balance of agricultural ecosystems because a great damage to non target species can lead to the restriction of natural enemies' populations. The objective of this research was to evaluate the effects of several different bacterial isolates on the efficacy of biological control of soil borne diseases. White rot caused by Sclerotium cepivorum was reported to be severe disease of garlic and chive. The antifungal bacteria Burkholderia pyrrocinia CAB08106-4 was tested in field bioassays for its ability to suppress white rot disease. In field tests, B. pyrrocinia CAB08106-4 isolates suppressed white rot in garlic and chive, with the average control efficacies of 69.6% and 58.9%, respectively. In addition, when a culture filtrate of B. pyrrocinia CAB08106-4 was sprayed onto wounded garlic bulbs after inoculation with a Penicillium hirstum spore suspension in a cold storage room ($-2^{\circ}C$), blue mold disease on garlic bulbs was suppressed, with a control efficacy of 79.2%. These results suggested that B. pyrrocinia CAB08106-4 isolates could be used as effective biological control agents against both soil-borne and post-harvest diseases of Liliaceae. Chinese cabbage clubroot caused by Plasmodiophora brassicae was found to be highly virulent in Chinese cabbage, turnips, and cabbage. In this study, the endophytic bacterium Flavobacterium hercynium EPB-C313, which was isolated from Chinese cabbage tissues, was investigated for its antimicrobial activity by inactivating resting spores and its control effects on clubroot disease using bioassays. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivated the resting spores of P. brassicae, with the control efficacies of 90.4%, 36.8%, and 26.0%, respectively. Complex treatments greatly enhanced the control efficacy by 63.7% in a field of 50% diseased plants by incorporating pellets containing organic matter and F. hercynium EPB-C313 in soil, drenching seedlings with a culture solution of F. hercynium EPB-C313, and drenching soil for 10 days after planting. Soft rot caused by Pectobacterium carotovorum subsp. carotovorum was reported to be severe disease to Chinese cabbage in spring seasons. The antifungal bacterium, Bacillus sp. CAB12243-2 suppresses the soft rot disease on Chinese cabbage with 73.0% control efficacy in greenhouse assay. This isolate will increase the utilization of rhizobacteria species as biocontrol agents against soft rot disease of vegetable crops. Sclerotinia rot caused by Sclerotinia sclerotiorum has been reported on lettuce during winter. An antifungal isolate of Pseudomonas corrugata CAB07024-3 was tested in field bioassays for its ability to suppress scleritinia rot. This antagonistic microorganism showed four-year average effects of 63.1% of the control in the same field. Furthermore, P. corrugata CAB07024-3 has a wide antifungal spectrum against plant pathogens, including Sclerotinia sclerotiorum, Sclerotium cepivorum, Botrytis cinerea, Colletotrichum gloeosporioides, Phytophotra capsici, and Pythium myriotylum.

• Korean Journal of Microbiology
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• v.42 no.3
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• pp.223-229
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• 2006

To develop multifunctional microbial inoculant, an insluble phosphate-solubilizing bacterium with antifungal activity was isolated from plant rhizospheric soil. On the basis of its morphological, cultural and physiological characteristics and Biolog analysis, this bacterium was identified as Pseudomonas fluorescens RAF15. P. fluorescens RAF15 showed antifungal activities against phytopathogenic fungi Botrytis cinerea and Rhizoctonia solani. The optimal medium composition and cultural conditions for the solubilization of insoluble phosphate by P. fluorescens RAF15 were 1.5% of glucose, 0.005% of urea, 0.3% $MgCl_2{\cdot}6H_2\;0.01%\;of\;MgSO_4{\cdot}7H_2O\;0.01%,\;of\;CaCl_2{\cdot}2H_2O$, and 0.05% of NaCl along with initial pH 7.0 at $30^{\circ}C$. The soluble phosphate production under optimum condition was 863 mg/L after 5 days of cultivation. The solubilization of insoluble phosphates was associated with a drop in the pH of the culture medium. P. fluorescens RAF15 showed resistance against different environmental stresses like $10-35^{\circ}C$ temperature, 1-4% salt concentration and pH 2-11 range. The strain produced soluble phosphate to the culture broth with the concentrations of 971-1121 mg/L against $CaHPO_4$, 791-908 mg/L against $Ca_3(PO_4){_2}$, and 844 mg/L against hydroxyapatite, respectively. However, the strain produced soluble phosphate to the culture broth with the concentrations of 15 mg/L against $FePO_4$, and 5 mg/L against $AlPO_4$, respectively.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.212-219
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• 2016

Forty-nine pigments were extracted from the collections of 106 pigment producing bacteria from the plant rhizosphere soil. Antibacterial activity test was performed in the subjects of the extracted pigments with plant pathogenic bacteria including Xanthomonas axonopodis and Xanthomonas campestris, and with plant pathogenic fungi including Botrytis cinerea, Colletotrichum acutatum, and Fusarium oxysporum. The yellow pigment by Chryseobacterium sp. RBR9 and the red pigment by of Methylobacterium sp. RI13 showed the antibacterial activities against Xanthomonas axonopodis and Xanthomonas campestris. The violet pigment by Collimonas sp. DEC-B5 showed the antibacterial activity as well as the antifungal activities against Botrytis cinerea and Fusarium oxysporum. Especially, the violet pigment inhibited the growth of Botrytis cinerea more than 65% at MIC $20{\mu}M$. Upon the HPLC analysis result for the isolation of pigment with antifungal activity, violacein (91.6%) and deoxyviolacein (8.4%) were isolated for the pigment by Collimonas sp. DEC-B5. The production amount of the pigment was increased more than 10 times higher when D-mannitol 1.5% and yeast extract 0.2% were added as the nitrogen source to SCB medium. This study suggests that produced violacein by Collimonas sp. DEC-B5 will be effective to control strawberry gray-mold rot fungi by its preventive activity.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.280.2-280
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• 1998

No Abstract, See Full Text