• 농약과학회지
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• 제15권4호
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• pp.495-501
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• 2011

한라산에서 해발 1000미터부터 100미터의 고도 간격으로 산림토양 샘플을 채집하고 총 398점의 토양 세균을 분리하여 항균 및 단백질 분해활성과 Auxin 생산특성을 규명하였다. 항균활성 균주를 선발하기 위해 주요 작물병원균 8종에 대하여 대치배양한 결과 여러 종의 병원균에 대해 항균활성을 가지는 26균주를 1차적으로 선발하였으며, 단백질 분해활성이 높은 34균주, Auxin을 생산하는 26균주도 함께 선발하였다. 토마토잿빛곰팡이병에 대한 생물검정 결과 Je28-4(Rhodococcus sp.)가 80%의 방제효과를 나타내었다. 한라산에서 분리한 항균 및 단백질 분해활성, Auxin 생산균주 중 대표적인 균주를 선발하여 종을 동정한 결과 다양한 속에 속하는 미생물이 동정되었으며 Bacillus 속이 12균주로 가장 많았고 Streptomyces 8균주, Paenibacillus 속 5균주, Chryseobacterium 속 5균주, Pseudomonas 속 4균주, Rahnella 속 2균주, Lysinibacillus 속 2균주, Burkholderia 속 2균주로 동정되었으며, Enterobacter, Janthinobacterium, Microbacterium, Rhodococcus, Sphingomonas 속은 각각 1균주씩 동정되었다. 본 실험 결과 선발된 균주들은 추후 다각도의 in vitro 검정 및 생물검정을 걸쳐 식물 생장촉진 및 병 방제용 다기능성 미생물 자재의 소재로 활용 가능성을 검토할 필요가 있다고 사료된다.

• 한국미생물·생명공학회지
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• 제38권3호
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• pp.322-328
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• 2010

발효홍어(홍어회)에 존재하는 박테리아 집단의 다양성을 확인하기 위해, 박테리아의 16S rDNA 절편들을 증폭하고 클로닝하여 라이브러리를 구축하였다. 삽입 서열의 염기서열을 결정한 후, BLAST 분석에 의해 미생물 동정을 하였다. 동일한 삽입서열 빈도를 계산하였을 때, 발효홍어(홍어회)에는 uncultured bacterium clone 054E11.b가 57.1% 나타남으로써 우점균으로 존재하고 있다고 추정하였다. 또한 발효홍어(홍어회) 현탁액을 한천배지에 도말하여 형성된 집락을 콜로니 PCR을 수행하였을 때, Pseudomonas sp. KC-EPS13 등 12 종의 박테리아가 동정되었다. 배양 의존적 방법과 배양 비의존적 방법으로 홍어회를 분석하였을 때, Psychrobacter sp. J466만이 두 가지 방법에서 모두 검출되었고 나머지 박테리아들의 균총은 상이하였다.

• KSBB Journal
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• 제9권3호
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• pp.246-252
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• 1994

유기용매 THF에서 bis(2, 2, 2-trichloroethyl) glutarate와 diol을 기질로 하여 PPL에 의한 tran sesterification 반응을 통해 polyester를 합성하였다. 1. 서로 다른 source의 lipase로 이 반응을 시켜본 결과 PPL이 가장 반응을 잘 진행시켰으며 Humi cola lanuginos와 Pseudomonas sp.의 Ii pase들도 어느 정도 반응을 진행사켰으며 Rhizopus의 lipase들 은 반응을 전혀 진행시키지 못했다. 2. Diol로 ethyleneglycol, 1, 3~propanediol, 1,4­b butanedi이은 모두 거의 비슷한 정도로 반응이 진행 되었으며 secondary alcohol인 glycerol의 경우 이들에 비해 반응이 매우 느리게 진행되었다. 이는 glycer이 에 의 해 효소가 steric hinderance를 받기 때문인 것으로 추정된다. 3. Diol로 여러 가지 분자량의 PEG(M = 300-1000)를 사용한 결과 PEG-400이 가장 잘 반응되었으며 이를 제외하고는 분자량이 클수록, 즉 chain의 길이가 갈수록 반응속도가 느렸다. 그리고 이렇게 chain의 길이가 비교적 긴($C_{12}-C_{45}$) PEG플 diol 로 사용했을 때는 monotransesterication 반응이 끝 난 이후에는 반응이 거의 더 이상 진행되지 않았다. 4. 유기용매로는 비교적 hydrophilic한 THF, ether, acetonitrile 등에 셔 잘 반응되었다. 5. $20^{\circ}C$ 에서 $60^{\circ}C$의 온도범위에서 반응온도가 높 을수록 반응속도가 빨랐으며 184시간 반응된 반응 생 생물의 평균분자량은 모두 2200←2300 daltons로 반응온도의 영향을 받지 않는 것으로 관찰되었다. 8. NMR에 의한 end group analysis를 이용하여 반응 생성물을 분석한 결과 수평균분자량은 1500­4 4000 daltons이었다.

• Animal cells and systems
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• 제3권2호
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• pp.221-228
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• 1999

In order to find a biochemical marker for late Iysosomes, we characterized two cDNAs which were cloned by using a monoclonal antibody (mAb) against Iysosomes in Amoeba proteus as a probe. The two cDNAs, a 1.3-kb cDNA in pBSK-Iys45 and a 1.6-kb cDNA in pBSK-Iys60, were found to encode proteins homologous to pepstatin-insensitive carboxyl proteinases (PICPs). E. coli transformed with pBSK-Iys45 produced two immunopositive polypeptides (45 and 43 kDa) and the cDNA in 1274 bases encoded a 44,733-Da protein (Lys45) of 420 amino acids containing one site for a core oligosaccharide. On the other hand, E. coli transformed with pBSK-Iys60 produced several polypeptides (64, 54, 45, 41, and 37 kDa) reacting with the mAb. The cDNA contained 1629 bases and encoded a 59,231-Da protein (Lys60) of 530 amino acids containing two sites for asparagine-linked core oligosaccharides. These two cDNAs showed identities of 60.3% in nucleotide sequences and 23.6% in amino acid sequences. Lys45 and Lys60 appeared to share XXEFQK as a common antigenic domain. The amino acid sequence of the Lys45 protein showed 17.4% identity and 40.9% similarity to that of PICP from Pseudomonas sp. 101. On the other hand, Lys60 showed a 24.3% identity and 51.9% similarity with human Iysosomal PICP in the amino acid sequence. A putative active center for serine protease, GTS＊xxxxxFxG, was found to be conserved among PICP homologues. The two PICPs are the first reported enzymatic markers for late Iysosomes.

• 대한수의학회지
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• 제15권1호
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• pp.83-91
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• 1975

A total of 119 raw milk samples from ten dairy farms were examined for total bacterial count, and 739 quarter milk samples of 118 dairy cows of 14 herds were examined for mastitis. The results obtained were as follows: 1. The mean of total bacterial counts of the 119 raw milk samples was 132,000 per ml. The total bacterial counts of 81 samples (68.1%) were under the standard of 100,000 per ml and those of the 38 samples (31. 9%) were over the standard. The number of bacteria showed a tendency to increase in summer. 2. One hundred and ninety five quarters (26.4%) of 98 cows (52.7%) were proved to be infected with mastitis. Clinical mastitis was found at 7 qtarters (3.5%) of 5 cows (5.0%). 3. Staphylococcus (44.9%) and Streptococcus (26.7%) were two main causative organisms of mastitis. Coliform bacteria (4.6%), Pseuedomonas spp. (4.6%), yeasts (1. 3%) and corynebacterium sp. (0.7%) were also isolated from the infected quarters. 4. The isolates were more sensitive to chloramphenicol ((96.1%), leukomycin (78.8%), streptomycin (75.5%) and tetracycline (72.4%). On the other hand, they were less sensitive to colistin (11.0%), oreandomycin (18.1%), sulfisoxazole (24.6%), penicilline (27.6%), kanamycin (43.3%) and erythromycin (49.7%). Especially the strains of Pseudomonas spp. isolated from the infected quarters were resistant to almost all the drugs examined.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.257-260
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• 2001

유기용매 내성 균주를 분리하기 위해서 석유화학 공업단지 부근의 폐수 및 토양을 채취하여 각종 유기용매에 적응시킨 후 순수 분리를 통하여 내성을 가진 균주를 분리하였으며 그 중에 서 가장 내성이 강한 균주 BCND 106, 154 and 171 을 분리하였다. 이 균주를 이용하여 유기용매 내성 및 분해능 검사를 하였다. 그 결과 이 세 균주는 본 실험에 사용한 유기용매 대부분에 대해서 내성을 나타내었으며, 또한 이를 탄소원으로도 이용하였다. 특히 BCNU 106 과 171 은 xylene isomer 인 meta-, para-xylene을 탄소원으로 이용할 뿐아니라 특히 독성이 강한 것으로 알려져 있는 ortho-xylene도 동시에 분해하는 것으로 알 수 있었다. 또한 항생제와 중금속에 대해서도 강한 내성을 나타내었는데, 이는 유기용매 내성 기작과 밀집한 관련이 있는 것으로 판단한다.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.89-95
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• 1997

The current processer of the textile wastewater treatment are mostly consisted of a combination of a physico-chemical and a biological treatment. The overall efficiency of these processes is, however, assessed to be fairly low. It is even worse during the summer season when temperature of the wastewater rises above 40$\circ $C. Therefore, a feasible process of the textile wastewater treatment which can work efficiently at higher temperatures was investigated in this work. We used a bench scale reactor consisted of one 4 liter anaerobic and one 8 liter aerobic tank, and the thermophilic symbiotic PVA degraders, Pasteruella hemolytica KMG1 and Pseudomonas sp. KMG6 that had been isolated in our laboratory. In the preliminary flask experiments, we observed that the thermophilic symbiotic PVA degraders could not grow in the wastewater substrate. Then, we isolated the mutant strains by acclimating the KMG1and KMG6 strains to the wastewater medium. The mutant symbionts (KMG1-1 and KMG6-1) were isolated through 6 times successive transfers into the fresh wastewater medium after 5 days culture for each. The mutant strains obtained grew well in the mixed medium composed of 75% wastewater and 25% synthetic medium, and supplemented with 0.5% PVA as a sole carbon source. During the culture for 14 days at pH 7.0 and 40$\CIRC $C, the bacteria assimilated about 89% of the added PVA. The symbionts degraded equally well all the PVA substrates of different molecular weight (nd=500~30000). In contrast to the flask experiments, in the reactor system the mutant strains showed very low levels of the PVA and COD removal rates. However, the new reactor system with an additional aerobic tank attained 82% removal rate of COD, 94% of PVA degradation and 71% of color index under the conditions of 5% inoculm on the tank 2, incubation temperature of 40$\circ $C, dissolved oxygen level of 2~3 mg/l and retention time of 30 hours. This result ensures that the process described above could be an efficient and feasible treatment for the PVA contained textile wastewater at higher temperatures.

• KSBB Journal
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• 제19권4호
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• pp.331-334
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• 2004

재조합 E. coli를 이용한 MCL-PHA의 생산에서 fatty acid pathway로부터 PHA 생합성 전구체 물질들이 만들어진다는 사실과 함께 이에 관여하는 enzymes이 밝혀지고 있다. 본 논문에서는 protein homology search로부터 탐색된 paaG와 ydbU genes의 PHA 생합성에서의 역할을 확인하기 위하여 paaG와 ydbU gene이 각각 knock-out된 mutant E. coli strains 를 제작하였다. 제작된 mutant E. coli들은 모균주들보다 낮은 PHA 농도와 함량을 가졌으며, 이러한 결과들로부터 paaG와 ydbU는 fatty acid pathway에서 PHA synthesis의 전구체 물질들을 공급한다는 사실을 확인하였다. 또한, 새로운 FadB homologous enzyme YgfG를 탐색하였으며, ygfG gene이 overexpression된 균주와 ygfG mutant를 제작하여 PHA 합성을 실험한 결과 ygfG도 paaG와 ydbU와 유사한 역할을 한다는 사실을 밝혔다. 이러한 연구결과들은 E. coli에서의 MCL-PHA 단량체들의 합성 경로를 확인하여 효과적인 PHA 생산 균주를 제작할 수 있게 할 것이다.

• Journal of Microbiology
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• 제42권3호
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• pp.188-193
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• 2004

Xanthobacter flavus strain UE15 was isolated in wastewater obtained from the Ulsan industrial complex, Korea. This strain functions as a 1,2-dichloroethane (1,2-DCA) degrader, via a mechanism of hydrolytic dechlorination, under aerobic conditions. The UE15 strain was also capable of dechlorinating other chloroaliphatics such as 2-chloroacetic acid and 2-chloropropionic acid. The dhlA gene encoding 1,2-DCA dechlorinase was cloned from the genomic DNA of the UE15 strain, and its nucleotide sequence was determined to consist of 933 base pairs. The deduced amino acid sequence of the DhlA dechlorinase exhibited 100％ homology with the corresponding enzyme from X. autotrophicus GJ10, but only 27 to 29％ homology with the corresponding enzymes from Rhodococcus rhodochrous, Pseudomonas pavonaceae, and Mycobacterium sp. strain GP1, which all dechlorinate haloalkane compounds. The UE15 strain has an ORF1 (1,356 bp) downstream from the dhlA gene. The OFR1 shows 99％ amino acid sequence homology with the transposase reported from X. autotrophicus GJ10. The transposase gene was not found in the vicinity of the dhlA in the GJ10 strain, but rather beside the dhlB gene coding for haloacid dechlorinase. The dhlA and dhlB genes were confirmed to be located at separate chromosomal loci in the Xanthobacter flavus UE15 strain as well as in X. autotrophicus GJ10. The dhlA and transposase the UE15 strain were found to be parenthesized by a pair of insertion sequences, 181247, which were also found on both sides of the transposase gene in the GJ10 strain. This unique structure of the dhlA gene organization in X. flavus strain UE15 suggested that the dechlorinase gene, dhlA, is transferred with the help of the transposase gene.

• Journal of Microbiology
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• 제42권3호
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• pp.216-222
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• 2004

In a previous paper, the ogdH gene that encodes 2-oxoglutarat dehydrogenase was isolated from Salmonella typhimurium. The catalytic N-terminal region in the enzyme was found to be very specific for the Salmonella species. Therefore, the aim of the present study was to detect S. typhimurium in food sources using primers designed for OGDH-l and OGDH-2 which were based on the salmonella-specific region of the ogdH gene. A simple polymerase chain reaction (PCR) detection method was developed to detect low numbers of S. typhimurium in a chicken meat microbial consortium. Using the ogdH-specific primers under stringent amplification conditions and for gene probe analysis, fewer than 100 colony-forming units (CFUs) were detectable when pure cultures were employed. When the PCR assay was run on S. typhimurium-contaminated meat contents, only the positive meat samples containing as few as 200 CFUs reacted to the assay. The method employed for sample processing is simple and it was determined to provide a sensitive means of detecting trace amounts of S. typhimurium-specific sequences in the presence of mixed meat microbial populations. When compared with six representative intestinal gram-negative bacterial strains in foods, including Vibrio parahaemolyticus, V. vulnificus, Enterobacter cloacae, E. coli O157:H7, Pseudomonas aeruginosa, and Proteus sp., S. typhimurium had a unique and distinct PCR product (796 bp). In conclusion, the two OGDH primers were found to be rapid and sensitive detectors of Salmonella spp for the PCR method.