• KSBB Journal
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• 제11권3호
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• pp.270-275
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• 1996

재조합 효모를 이용한 포도당산화효소의 대량생산 에 관한 기초연구를 실시하였다. 분비신호를 포함한 포도당산화효소 유전자는 Aspergillus niger로부터 polymerase chain reaction을 이용하여 클로닝한후 G GALl과 GALlO promoter를 이용하여 s. cerevi siae strain 2805에서 말현시킨 결과 GALl promoter를 사용한 형질전환체(yGOD1-l)에서 높은 효율 의 효소생성을 나타냈다. 플라스크 배양 결과 1% galactose를 포함한 YEP 배 지 에셔 최고 6 IU/mL 의 포도당산화효소를 생산하였으며 재조합 포도당산 화효소의 세포내 위치를 비교한 결과 A. niger와는 달리 발현된 효소가 80% 이상 배지로 분비됨을 확인하였다. 재조합 포도당산화효소의 열 안정성을 측정한 결과 표준품과 비교하여 $50^{\circ}C$까지 큰 차이를 보이지 않고 높은 활성을 유지하는 것으로 확인되었다.

• 미생물학회지
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• 제32권3호
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• pp.186-191
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• 1994

Staphylococcus aureus로부터 분리한 R-plasmid pSBK203의 복제개시 단백질인 Rep의 작용부위인 ori 및 dsDNA로의 전환을 위해 요구되는 minus origin부위를 밝히고자 시도하였다. Escherichia coli vecotr를 이용하여 pSBK203의 복제관련 부위를 최소한도로 포함하는 재조합 E.coli-Bacillus subtilis shuttle vector를 구성, 분리하고 여기에 포함된 pSBK203부위의 염기 서열을 분석함으로써 ori를 확인하였다. pSBK203의 복제개시 부위 ori는 rep의 구조 유전자 ORF내에서 약 50bp의 크기로 발견되었으며 지금까지 알려진 staphylococcal plasmid들중에서 pT181족 plasmid들의 ori와 높은 상동성을 갖는 것으로 분석되었다. 복제 과정에서 ssDNA로 먼저 만들어진 (+)쇄가 dsDNA로 전환되기 위해 필요한 신호로 작용하는 것으로 알려저 있는 minus origin (M-O)인 긴 palindrome 구조, 즉 pal 부위가 rep 우전자의 상류에서 2개 연이어 존재하는 것이 발견되었다. 이중에서 pOX6, pC194, 및 pE194 등과 같은 다른 staphylococcal plasmid들의 pal 부위와 비교적 높은 상동성을 갖는 paLA 는 plasmid 유지에 별 영향을 미치지 못하는 반면 다른 plasmid에서 유사 서열이 보고되지 않은 palA는 plasmid 유지에 필수적이라는 사실이 밝혀졌다.

• 한국잠사곤충학회지
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• 제36권2호
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• pp.157-161
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• 1994

B. thuringiensis subsp. kurstaki Cry-B에서 cryIA(b) 유전자 promoter 조적을 받는 cryIA(c) 유전자와 그 자신의 promoter 조절을 받는 cryIIA 유전자의 발현 여부와 내독소 단백질의 형태를 관찰하기 위하여, 이들 두 내독소 단백질 유전자를 B.thuringiensis - E. coli shuttle vector를 이용하여 발현벡터 pKC1A와 pKC2A를 각각 제작하였다. 발현벡터 pKC1A와 pKC2A를 B. thuringiensis subsp. kurstaki Cry-B 균주에 형질전환시키고, 이들 형질전환체로부터 각각 bipyramid형과 cuboid형의 정상적인 내독소 단백질이 발현되었음을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제16권1호
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• pp.149-152
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• 2006

Leuconostoc mesenteroides SY1, a strain isolated from cabbage Kimchi, was transformed with pCW4, a shuttle vector based on a cryptic plasmid from Lactobacillus paraplantarum C7. $\alpha-Amylase$ gene, amyL, from Bacillus licheniformis was cloned into pCW4, resulting in $pCW4T{\alpha},\;and\;pCW4T{\alpha}$ was introduced into SY1 by electroporation. Transformation efficiency was $10^2cells/{\mu}g$ plasmid DNA. L. mesenteroides cells harboring $pCW4T{\alpha}$ did not show amylase activity, although amyL transcript was synthesized as determined by slot blot experiment. $pCW4T{\alpha}$ was stably maintained in SY1 in the presence of erythromycin (Em, $5\;{\mu}g/ml$) but rapidly lost when Em was omitted. Less than $1\%$ of the cells maintained $pCW4T{\alpha}$ after 5 days at $30^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제2권4호
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• pp.243-247
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• 1992

The thr operon of Escherichia coli TF427, an $\alpha$-amino-$\beta$-hydroxyvaleric acid (AHV)-resistant threonine overproducer, was cloned in a pBluescriptII $KS^＋$ plasmid by complementation of E. coli mutants. All clones contained a common 8.8 kb HindIII-generated DNA fragment and complemented the thrA, thrB, and thrC mutants by showing that these clones contained the whole thr operon. This thr operon was subcloned in the plasmid vectors pBR322, pUC18, and pECCG117, an E. coli/Corynebacterium glutamicum shuttle vector, to form recombinant plasmids pBTF11, pUTF25 and pGTF18, respectively. The subcloned thr operon was shown to be present in a 6.0 kb insert. A transformant of E. coli TF125 with pBTF11 showed an 8~11 fold higher aspartokinase I activity, and 15~20 fold higher L-threonine production than TF125, an AHV-sensitive methionine auxotroph. Also, it was found that the aspartokinase I activity of E. coli TF125 harboring pBTF11 was not inhibited by threonine and its synthesis was not repressed by threonine plus isoleucine.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.997-1004
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• 2009

Bacillus amyloliquefancies CH51 isolated from cheonggukjang, a traditional Korean fermented soy food, has strong fibrinolytic activity and produces several fibrinolytic enzymes. Among four different growth media, tryptic soy broth was the best in terms of supporting cell growth and fibrinolytic activity of this strain. A protein with fibrinolytic activity was partially purified from the culture supernatant by CM-Sephadex and Phenyl Sepharose column chromatographies. Tandem mass spectrometric analysis showed that this protein is a homolog of AprE from B. subtilis and it was accordingly named AprE51. The optimum pH and temperature for partially purified AprE51 activity were 6.0 and $45^{\circ}C$, respectively. A gene encoding AprE51, aprE51, was cloned from B. amyloliquefaciens CH51 genomic DNA. The aprE51 gene was overexpressed in heterologous B. subtilis strains deficient in fibrinolytic activity using an E. coli-Bacillus shuttle vector, pHY300PLK.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.356-361
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• 1991

식물근부병의 방제균으로 선발된 Bacillus subtilis YBL-7의 식물부균 Fusarium solani에 대한 길항력을 유전공학적 조작에 의해 다목적으로 증강시킬 수 있는지를 타진하기 위해 외부유전자인 Bacillus pasteurii의 urease 유전자를 생물방제균 B.subtilis YBL-7내 도입자하고자 시도하였다. 외부 urease 유전자는 B.pasteurii의 urease gene을 shuttle vector인 pGR71의 HindII site에 삽입하여 E.coli내에서 발현시킨 pGU66을 사용하여 형질전환시켰으며 이때의 최적 형질전환조건과 도입된 urease 유전자의 발현을 조사해 보았다.

• BMB Reports
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• 제34권4호
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• pp.379-384
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• 2001

The cDNA encoding ribosomal protein was identified from a cDNA library of Schizosaccharomyces pombe. The nucleotide sequence of the 548 by cDNA clone reveals an open reading frame, which encodes a putative protein of 166 amino acids with a molecular mass of 18.3 kDa. The amino acid sequence of the S. pombe L11 protein is highly homologous with those of rat and fruit, while it is clearly less similar to those of prokaryotic counterparts. The 1,044 by upstream sequence, and the region encoding N-terminal 7 amino acids of the genomic DNA were fused into the promoterless $\beta$-galactosidase gene of the shuttle vector YEp357 in order to generate the fusion plasmid pHY L11. Synthesis of $\beta$-galactosidase from the fusion plasmid varied according to the growth curve. It decreased significantly in the growth-arrested yeast cells that were treated with aluminum chloride and mercuric chloride. However, it was enhanced by treatments with cadmium chloride ($2.5\;{\mu}M$), zinc chloride ($2.5\;{\mu}M$), and hydrogen peroxide (0.5 mM). This indicates that the expression of the L,11 gene could be induced by oxidative stress.

• Applied Biological Chemistry
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• 제40권3호
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• pp.173-177
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• 1997

Bacillus licheniformis 9945a는 액체배양시 ${\gamma}-poly(glutamic\;acid)$를 균체외로 분비하며, 한천배지에 고체 배양시는 점액질의 군락을 나타낸다. 점액질의 Bacillus속 세균의 형질전환은 그리 순하지 않은 것으로 알려져 있으며, B. licheniformis에서의 trasposon Tn10의 활성여부도 알려져 있지 않다. 그래서 점액질을 분비하지 않는, B. licheniformis의 자연발생적 변이주를 우선 분리하였다. Mini-Tn10을 함유한 plasmid pHV1248을 protoplast transformation법에 준해서 이 변이주에 도입하여 형질전환체를 분리하였다. pHV1248을 함유한 형질전환체를 점액성의 야생형질로 복귀시킨 후에, 가열처리함으로써 무작위 돌연변이를 유도하였다. Arginine, lysine 또는 tryptohan을 생육인자로 요구하는 돌연변이주들이 replica plating method에 의해서 분리되었고, 이 들 영양요구성 변이주는 mini-Tn10이 염색체 DNA상에 삽입됨으로써 생겨났음이 Southern blotting과 DNA-DNA 혼성화 실험으로 증명되었다. 이러한 pHV1248을 이용한 형질전환 및 돌연변이 유도방법은 Bacillus licheniformis 9945a의 다양한 변이체를 얻는데 유용할 것이다.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.508-514
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• 2001

A stuructural gene (ycl) encoding novel yeast cell wall hydrolase, YCL, was cloned from alkalophilic Bacillus alcalophilus subsp. YB380 by PCR, and transformed into E. coli JM83. Based on the N-terminal and internal amino acid sequences of the enzyme, primers were designed for PCr. The positive clone that harbors 1.8 kb of the yeast cell wall hydrolase gene was selected by the colony hybridization method with a PCR fragment as a probe. According to the computer analysis, this gene contained a 400-base-paired N-terminal domain of the enzyme. Based on nucletide homology of the cloned gene, a 850 bp fragment was amplified and the C-terminal domain of the enzyme was sequenced. With a combination of the two sequences, a full nucleotide sequence for YCL was obtained. This gene, ycl, consisted of 1,297 nucleotides with 27 nucleotides with 27 amino acids of signal sequence, 83 redundant amino acids of prosequence, and 265 amino acids of the mature protein. This gene was then cloned into the pJH27 shuttle vector and transformed into the Bacillus subtilis DB104 to express the enzyme. It was confirmed that the expressed cell wall hydrolase that was produced by Bacillus subtilis DB104 was the same as that of the donor strain, by Western blot using polyclonal antibody (IgY) prepared from White Leghorn hen. Purified yeast cell wall hydrolase and expressed recombinant protein showed a single band at the same position in the Western blot analysis.