• Korean Journal of Microbiology
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• v.19 no.3
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• pp.115-120
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• 1981

The substance produced by Bacillus subtilis $480HS_{20}$ showed specific anti Puccinia graminis activity and narrow antimicrobial activity. The anti Puccinia graminis substance was found to be peptide antibiotic which had molecular weight of about 1,500 by sephadex LH-60 gel-filtration. The amino acid composition of the substance waas composed of Ser (1), Glu(3), Ile(1), Gyr(2) and His (1). The compound was yellowish powder and it's melting point was $214{\sim}216^{\circ}C$. UV spectrum in methanol showed single peak at 278(E 1% 1cm 15.2) and important peak at 3,350-3,320, 2,940, 1,635, 1,520-155, 1,240-1, $230cm^{-1}$ were observed in IR Spectrum. The substance was soluble in methanol but insoluble in water, ethyl acetate and chloroform. The antibiotic $480HS_{20}$ showed a little antimicrobial activity against Pyricularia aryzae but no antimicrobial activity was observed against Gram + and Gram - bacteria and molds except pyricularia oryzae.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.18-24
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• 2002

The present study was performed to investigate the excellent microbial anticaries substance, aminoglycoside antibiotic, which is more effective than chlorhexidine for the treatment of dental caries. The aminoglycoside antibiotic against Streptococcus mutans JC-2 from a novel alkaliphilic Bacillus alkalophilshaggy JY-827 exhibited no significant difference at the treatment concentration of $2.5{\times}10^{-7}M$, however, it inhibited the activity of the Streptococcus mutans glucosyltransferase by 70.2% and 99.8% at the concentrations of $2.5{\times}10^{-7}$M\;and\;2.5{\times}10^{-6}M$, respectively. Lineweaver-Burk plot of the inhibitory aminoglycoside antibiotic showed competitive inhibition, with $K_i$ value of $6.4{\times}10^{-6}$ M. The aminoglycoside antibiotic did not show any cytotoxicity against human gingival cells. To evaluate the industrial applicability of the aminoglycoside antibiotic, a toothpaste containing this substance was prepared and tested on the extracted human teeth. The inhibitory rate of tooth calcification and calcium ion elution by the aminoglycoside antibiotic were 50% and 2.5 times, respectively. These results suggested that the aminoglycoside antibiotic from Bacillus alkalophilshaggy JY-827 is an effective agent against dental caries.

• The Plant Pathology Journal
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• v.17 no.1
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• pp.52-56
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• 2001

This study was undertaken to separate and identify antifungla substances produced by Gilocladium virens G1, a biocontrol agent used for the control of plant diseases caused by Rhizoctonea solani. The culture of G. virens G1 effectively inhibited the growth of R. solani, Colletotrichum gloeosporioides, and Phytophthora capsici, but less that of Fusarium oxysporum. The n-hexane extract of the G. virens culture, which was used for the purification of responsible substances, strongly inhibited R. solani and C. gloeosporioides, but not P. capsici, although the n-butanol extract was effective on all of the pathogens tested. An antifungal substance was purified using the n-hexane extract by Silica gel column chromatography and HPLC. The substance was examined for purity by HPLC and for nature by UV spectrometry, which differed from known antibiotic compounds such as gliotoxin, viridin and gliovirin. The antifungal substance was very liphophilic based on its solvent-solubility and Rf values on TLC, and more inhibitory to C. gloeosporioides than other fungal pathogens tested.

• Journal of Life Science
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• v.19 no.5
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• pp.676-679
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• 2009

In order to produce a new antibiotic material against Jurkat T cells using horizontal gene transfer among microbes, co-cultures between soil bacteria AY2000 and the multiple antibiotic producer S. griseus was carried out. It showed that the highest active substance against Jurkat T cells was produced at 48 hr of co-culture time with MTT assay. Moreover, a morphological change of nuclear of Jurkat T cells treated with co-cultured substance was observed in DAPI staining. This result suggests that a new material was produced with co-culture supernatant, and that co-culture between microboes can develop new antibiotic materials.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.253-258
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• 2007

Bombycis corpus, a batryticated silkworm and white-stiff silkworm, is an oriental drug consisting of the dried larva of silkworm, dead and stiffened due to the infection of Beauveria. An peptidyl antimicrobial molecule was purified from B. corpus by reverse phase-column chromatography and HPLC. Its molecular weight was determined to be 2295.45 by using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Its antimicrobial activity was diminished by trypsin digestion. It exhibited a broad antimicrobial spectrum against not only Gram-negative, but also Gram- positive bacteria. Furthermore, it was found to have an antimicrobial activity against vancomycin-resistant enterococci (VRE), methicillin-resistant S. arureus (MRSA), and vancomycin-intermediate resistant S. arureus (VISA). It may be a useful molecule for a new antibiotic development, especially against antibiotic resistant microbe. This substance may play a role in the defense system of this animal against Beauveria bassiana. This is the first report of a peptidyl antimicrobial substance from B. corpus.

• Microbiology and Biotechnology Letters
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• v.3 no.2
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• pp.69-72
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• 1975

Isolation of the toxic substance which was produced by Streptentyces sp. and it's biorhemical characterestics and toxicity to fishes were reported in the previous paper. The present report includes antibiotic activity of the substance, inhibitory activity of the substance on the succinic dehydrogenase of fishes, and its effect on the blood corpuscles of a rabbit. An evident antibiotic activity of this substance was observed on Candida yeasts, but n$ot^1$on molds or bacteria. The substance inhibited the growth of Candida japonica and C. utilis to the 50％ at the concentrations of 7.5 and 10.2ug per ml, respectively. The activity of succinic dehydrogenase obtained from various organs of Cyprinous carpio L. was also found to be inhibited by this substance. Original activities of the enzymes from tht brain, kidney, and liver, were inhibited by 75.4％, 38.2％, and 26.2％, respectively, but not the enzymes from the heart and spleen. Neither leukopenia nor leukocytosis was detected after the intravenous administration of the substince to the rabbit at the level of 6 mg per 2 kg body weight.

• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.40-44
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• 2018

An isolate capable of inhibiting the growth of gram-positive bacteria was obtained from the soil of Mushim stream, Cheongju. The isolate was identified as Pseudomonas otitidis PS by 16S rRNA gene sequence analysis. P. otitidis PS produced antibiotics as a secondary metabolite when cultured in 1% soybean meal with 0.5% glucose. The maximum yield was about 0.1%. The antibiotic substance of P. otitidis PS extracted using ethyl acetate displayed a minimum inhibitory concentration of $2{\mu}g/ml$ for Staphylococcus aureus KCTC 1261. The antibiotic substance produced an orange halo on chrome azurol S agar due to siderophore activity. Growth inhibition was decreased when the iron was depleted. Since the antibiotic activity was lost upon the addition of the reducing agent ascorbic acid or during anaerobic culture, it was considered that antibiotic of P. otitidis PS strain exerts its bactericidal effect by the generation of reactive oxygen species.

• Journal of Environmental Health Sciences
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• v.32 no.5 s.92
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• pp.462-468
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• 2006

Antibiotics are manufactured and used for specific physiological functions, hence they may exert adverse ecological consequences when they are in contact with nontarget organisms. In the last decade, many reports have been made on the occurrences of various antibiotic compounds in surface water, and their potential impact to the environment has become an increasing concern. This study was conducted to prioritize antibiotic substances with potential environment risk in Korea. Human use antibiotics with an EIC (Expected Introduction Concentration) value greater than $1{\mu}g/l$, US FDA's action limit criteria, were selected. In order to calculate a worst-case EIC for each substance, annual production volume (in kg) of each antibiotic substance was derived using the Korea Pharmaceutical Manufacturers Association (KPMA)'s monetary database. Sixteen substances were preliminarily selected. The EICs of the 16 antibiotic substances were refined with the excretion rate of the parent substances. Ten antibiotic substances were identified to have EIC-corrected greater than $1{\mu}g/l$, which include Amoxicillin ($15.8{\mu}g/l$), Cefaclor ($10.1{\mu}/l$), Roxithromycin ($4.2{\mu}g/l$), Cephradine ($4.5{\mu}g/l$), Cefatrizine ($2.6{\mu}g/l$), Cefadroxil ($3.3{\mu}g/l$), Aztreonam ($2.3{\mu}g/l$), Ceftazidime ($2.8{\mu}g/l$), Ribostamycin ($1.3{\mu}g/l$), and Ceftezole ($1.3{\mu}g/l$). Additional risk assessments for these antibiotic substances are suggested.

• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.349-353
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• 1999

Antagonistic Promicromonospora sp. KH-28 isolated from a suppressive soil could produced a chitinase and a antifungal antibiotic for the biocontrol ability. The chitinase and the antibiotic appeared to inhibit plant pathogens of Fusarium oxysporum. Phytophthora capsici, Alternaria kiki, fusarium solani, Stemphylium sp., and Psudomonas fluorescens. the antibiotic produced from the strain was identified as a antifungal substance of 503 dalton having a pyrimidine skeleton with an aliphatic side chain. The Promicromonospora sp. KH-28 was able to suppress effectively F. oxysporum derived-fusarium wilt of red-pepper plant in the pot in vivo test.

• Microbiology and Biotechnology Letters
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• v.18 no.4
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• pp.331-337
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• 1990

An antitumor antibiotic named B-1123 substance was isolated from the culture filtrate of a new isolate fungus identified as Aspergillus terreus. The fermentation yield reached about 23 mg per liter of the broth. The B-1123 substance, chlorine containing antibiotic, has the molecular formular of $C_{17}H_{12}0_7C_{12}$. Its structure was determined to be geodin by spectroscopic data. It is active against some Gram-positive bacteria and it prolongs the life span of mice inoculated with Ehrlich carcinoma.