• 한국미생물·생명공학회지
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• 제17권3호
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• pp.198-201
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• 1989

토양에서 분리, 동정한 Steptomyces sp. GI 32의 glucose isomerase 생산은 sorbitol 1%, yeast extract 0.4%, tryptore 0.6%, 1 mM Fe$_2$(SO$_4$)$_3$의 조성을 가진 배지에서 초기 pH 7.0으로 조절하여 35$^{\circ}C$에서 약 18시간 진탕배양시 효소생산량이 최고로 240 units/mg이었다. 효소는 ammonium sulfate 분획, DEAE cellulose chromatography 등의 과정을 거쳐 부분정제한 결과 3배정도 효소 비활성이 증가하였다. 효소활성의 치적온도는 7$0^{\circ}C$이며, 최적 pH는 8.0이었다. 특히 효소의 열안정성이 7$0^{\circ}C$에서 1시간 가열하여도 전혀 실활되지 않았다.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.166-172
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• 1996

It is well known that actinomycetes would be useful for screening of biologically active compounds. Not only to isolate diverse actinomycete strains but to ferment those strains effectively would be important. Seven hundred and forty six strains were isolated from Cheju province, 216 strains were from Chungnam province, 158 strains were from the natural caves at Chungbuk and Kangwon provinces and 202 strains were from Chungwon area at Chungbuk province. All of these 1,322 strains were fermented on a small scale using two different media and tested for their antimicrobial activities against four bacterial strains and one yeast strain. As the result, 12.3% of those isolates were active against Staphylococcus aureus KCTC 1916, 7.6% were Staphylococcus aureus KCTC 1928, 3.9% were Escherichia coli KCTC 1924, 3.0% were Candida albicans KCTC 1940, and 2.2% were Salmonella typhimurium KCTC 1926. About 40% of those isolates showed antimicrobial activities at both two media but the others showed at either one. According to the genus of isolated strains, Streptomyces and Micromonospora showed activities with higher frequencies than others.

• Journal of Microbiology and Biotechnology
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• 제9권3호
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• pp.371-375
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• 1999

AL072 is a potent anti-Legionella antibiotic produced by Streptomyces strain AL91. The minimum inhibitory concentration (MIC) of AL072 against Legionella pneumophila was 0.2$\mu$g/ml. Bacterial growth was rapidly inhibited at the dose range between the MIC and 20 times of the MIC when the antibiotic was added at the mid-exponential phase. Ultrastructural changes in L. pneumophila were observed upon treatment with AL072. Under electron microscopical observation, the organisms treated with AL072 exhibited characteristic morphological changes in the cellular outer coat. Also irregular morphological changes, such as the formation of filamentous materials in the cytoplasm, an increase in the size and number of cytoplasmic vacuoles, the extruding of cytoplasmic contents, the formation of spheroplast and ghost cells, and blebbings in the cell wall were observed. Furthermore, immunoelectron microscopical observation of the group treated with the MIC showed that the immune complex attached mainly to the cell wall. The results of these experiments indicate that AL072, like the inhibitors of cell wall synthesis, act selectively on the cell wall of L. pneumophila.

• 생명과학회지
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• 제9권5호
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• pp.510-517
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• 1999

For the treatment of Korean food-wastes, three mesophilic and one thermophilic bacteria were isolated from soil and fermented fertilizers. The thermophilic Streptomyces sp. strain WF021 produced two enzymes which were a protease and a lipase at 55$^{\circ}C$. The mesophilic Bacillus sp. strain WF024 produced four enzymes which were a protease, a lipase, a amylase and a cellulase when the strain was grown both at 3$0^{\circ}C$ and 55$^{\circ}C$. The Bacillus sp. PY123 had produced three enzymes which were a protease, a cellulase and a lipase at 3$0^{\circ}C$. The Bacillus sp. strain CM1 produced three enzymes which were a protease, a amylase, and a cellulase at 3$0^{\circ}C$. The bacteria were grown in media containing 6% NaCl at least and did not have antagonism each other. The four isolates treated much more food-wastes than referance strains did. In a flask without aeration, three reference strains treated 15.4% of food-wastes, while four isolates treated 23.7% of food-wastes. In a flask with aeration, food-wastes were treated 67.3% by four isolates, and 64.3% by three reference strains, but 53.9% without bacteria. However, food-wastes were treated about 78% in a 200$\ell$-reactor made by Siwon Co., while 65.8% in a 20$\ell$-reactor made by Sanyo Co.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.135-135
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• 1998

To find an antagonist of Pythium ultimum, the causal agent of damping-off, numerous actinomycete strains were screened for in vitro inhibiting mycelial growth of the target fungus and producing bioactive metabolites. A strain identified as Streptomyces sp. G60655 was isolated and used for further antagonistic efficacy. The degree of antagonism between the fungus and G60655 was affected by the medium used. Furthermore, the preinoculation of the antagonist was found to be necessary to exhibit the maximum efficacy of antagonsim against the fungus. From the culture broth, a bioactive metabolite was detected and purified by solvent extraction, silica gel chromatography and preparative HPLC. The FAB-MS spectrum of the active compound showed a molecular ion peak at m/z 1101 (M + H)$\^$+/, suggesting the molecular weight of 1100. The UV absorptions at 242 and 323 nm indicated the presence of aromatic functions. The structure of this compound was identified as echinomycin, a depsipeptide antibiotic by spectroscopic studies including various NMR measurements. Echinomycin was inactive against several soil born fungi, but inhibited the mycelial growth of P. ultimum and its related oomycetous fungi.

• 대한기관식도과학회지
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• 제9권2호
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• pp.60-64
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• 2003

Restenosis frequently develops with granulation and overgrowth of scar following surgical treatment for laryngotracheal stenosis. Various methods such as stenting or CO2 laser application have been used to prevent restenosis, but they were seldom unsatisfactory. Mitomycin is an antineoplastic antibiotics derived from Streptomyces caespitosus; it inhibits fibroblast proliferation and acts as an alkylating agent to inhibit DNA synthesis. This study was desinged to evaluate effectiveness and determine indications of usage of topical mitomycin for laryngotracheal stenosis as a nonsurgical means of reducing postoperative granulation and scar tissue formation. Patients and Method : A retrospective study was performed on eight cases of laryngotracheal stenosis with topical mitomycin application. The author analyzed clinical outcomes of operative treatment with topical mitomycin. Patients underwent laryngotracheal reconstruction, endoscopic granulation removal, or bronchoscopic bougienage followed by topical application of mitomycin (0.4 mg/$m{\ell}$, 4minuntes) on the lesion intraoperatively. Result : Overall success rate of decannulation was 38% ($\frac{3}{8}$). Successful decannulation was possible in 75% ($\frac{3}{4}$) of laryngeal stenosis patients, 75% ($\frac{3}{4}$) of children, 60% ($\frac{3}{5}$) of the patients without previous surgery, and 75% ($\frac{3}{4}$) of bronchoscopic bougienage. Conclusion : The topical application of mitomycin in laryngotracheal stenosis was effective in untreated pediatric laryngeal stenosis which underwent bronchoscopic bougienage. Our results show that the topical mitomycin application for laryngotracheal stenosis could be a effective adjuvant treatment.

• 한국식품영양학회지
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• 제12권3호
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• pp.271-278
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• 1999

We isolated activnmycetes LAM-98-80 as strain producing an effective antibiotic for cephalosporin re-sistant pathogenic PSeudomonas sp. and identified as Streptomyces sp. LAM-98-80 from cultural and phyisological characteristics. We investigated the optimal culture conditions for producation of an anti-biotic becoming effective for cephalsporin-resistant pathogenic Pseudomonas sp. It was found that 1.5% soluble starch and 1.0% yeast extract were good as carbon and nitrogen source respectively. The pro-duction of antibiotic was also activated by 0.04% Mn2+ as 80% degree. The optimum initial pH on pro-ductio of antibiotic was pH 7.0. The culture condition for the maximal productivity of the antibiotic was at 3$0^{\circ}C$ for 5 days. The cephalosporin-resistant pathogenic Pseudomonas sp. as test bacteria was rev-ealed to resist antibiotic of cepha families but revealed to not resist those of $\beta$-lactam families ampicil-lin and amoxicillin. Parital purified antibiotic was stable for the pH from 3 to 9 and was also stable when treated at 70 $^{\circ}C$ for 1 hour, This antbiotic was effective against all gram positive and negative bac-teria but was not effective against molds and yeasts.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.384-389
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• 1995

Streptoalloteichus hindustanus ATCC 31219, a nebramycin complex producer, is similar to Streptomyeces tenebrarius in a viewpoint of resistance to a wide range of aminoglycoside antibiotics. S. tenebrarius has resistance mechanisms of 16s rRNA methylation and aminogycoside modification. However, it is not known whether resistance mechanisms of Stall. hindustanus are the same as in S. tenebrarius. Therefore, we have tried to isolate resistance determinants from Stall. hindustanus. Two different types of aminoglycoside resistance determinants were isolated from Stall. hindustanus and expressed in Streptomyces lividans TK24. The apramycin resistance gene (amr) and the tobramycin resistance gene (tmr) isolated from Stall. hindustanus showed broad resistance spectrum against a dozen of aminoglycoside antibiotics. The complete nucleotide sequences of apramycin resistance gene (amr) were determined. The deduced amino acid sequence of the amr gene of Stall hindustanus ATCC 31219 showed extensive sequence homology to the 16s rRNA methylase gene (kamB) of S. tenebrarius.

• Journal of Microbiology and Biotechnology
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• 제21권3호
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• pp.263-266
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• 2011

Methylelaiophylin isolated from Streptomyces melanosporofaciens was selected as an ${\alpha}$-glucosidase inhibitor with an $IC_{50}$ value of 10 ${\mu}M$. It showed mixed-type inhibition of ${\alpha}$-glucosidase with a $K_i$ value of 5.94 ${\mu}M$. In addition, methylelaiophylin inhibited the intracellular trafficking of hemagglutinin-neuramidase (HN), a glycoprotein of Newcastle disease virus (NDV), in baby hamster kidney (BHK) cells. Methylelaiophylin inhibited the cell surface expression of NDV-HN glycoprotein without significantly affecting HN glycoprotein synthesis in NDV-infected BHK cells.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.885-892
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• 2011

The bacterial communities in the intestinal tracts of earthworm were investigated by culture-dependent and -independent approaches. In total, 72 and 55 pure cultures were isolated from the intestinal tracts of earthworms under aerobic and anaerobic conditions, respectively. Aerobic bacteria were classified as Aeromonas (40%), Bacillus (37%), Photobacterium (10%), Pseudomonas (7%), and Shewanella (6%). Anaerobic bacteria were classified as Aeromonas (52%), Bacillus (27%), Shewanella (12%), Paenibacillus (5%), Clostridium (2%), and Cellulosimicrobium (2%). The dominant microorganisms were Aeromonas and Bacillus species under both aerobic and anaerobic conditions. In all, 39 DNA fragments were identified by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Aeromonas sp. was the dominant microorganism in feeds, intestinal tracts, and casts of earthworms. The DGGE band intensity of Aeromonas from feeds, intestinal tracts, and casts of earthworms was 12.8%, 14.7%, and 15.1%, respectively. The other strains identified were Bacillus, Clostridium, Enterobacter, Photobacterium, Pseudomonas, Shewanella, Streptomyces, uncultured Chloroflexi bacterium, and uncultured bacterium. These results suggest that PCR-DGGE analysis was more efficient than the culturedependent approach for the investigation of bacterial diversity and the identification of unculturable microorganisms.