• 미생물학회지
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• 제29권6호
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• pp.408-415
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• 1991

TOL plsmid size of Flavobacterium odoratum SUB53 was estimated as 83 Md and the optimum concentration of m-toluate degradation by TOL plasmid was 5 mM. $H_{2}$ production by Rhodopseudomonas sphaeroides KCTC1425 was largely dependent on nitrogenase activity and showed the highest at 30 mM malate with 7 mM glutamate as nitrogen source. Nitrogenase activities were inhibited by 0.3 mM $NH_{4}^{+}$ions, to be appeared the decrease of $H_{2}$ production. Conjugation of TOL plasmids from F. odoratum SUB53 and Pseudomonas putida mt-2 to R. sphaeroides showed the optimum at the exponential stage of recipient cells in presence of helper plasmid pRK2013. According to the investigation of catechol-1,2-oxygenase (C-1, 2-O) and catechol-2,3-oxygenase (C-2,3-O) activities of R. sphaeroides C1 (TOL SUB53) and C2 (TOL mt-2), the gene for C-2,3-O is located on TOL plasmid and gene for C-1, 2-O on the chromosome of R. sphaeroides. m-Toluate was biodegraded by TOL plasmid in R. sphaeroides C1 and C2, presumably to be produced $H_{2}$ gas from the secondary metabolites of m-toluate.e.

• 미생물학회지
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• 제25권1호
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• pp.46-51
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• 1987

In order to increase the production of tryptophan by maximizing expression of recombinant trp plasmid, Klebsiella pneumoniae KC 105(pheA tyrA trpE trpR tyrR) was genetically modified. KC 107, inosine monophospate(IMP) auxotroph from KC 105 and KC 108, histidine(His) auxotroph from KC 107 were also derived respectively to increase phosphoribosylpyrophosphate(PRPP) production which is required for tryptophan biosynthesis. From KC 107 phosphoribosylpyrophosphate consumption which is required for tryptophan biosynthesis. From KC 107 and KC 108, KC 109 and KC 110, both arginine auxotrophs were derived respectively. To investigate the expression of recombinant trp plasmid in the selected K. pneumoniae mutants, the auxotrophic mutants were transformed with recombinant trp plasmids pSC 101-$trpE^{FBR}$, pSC 101-trpL(.DELTA.att) $trpE^{FBR}$ (pSC 101-trp-AF). Amount of tryptophan produced and activities of tryptophan synthase of $trpR^{-}$ mutant (KC 100) and $tyrR^{-}$ mutnat(KC 105) containing recombinant plasmid pSC 101-trp operon were increased by 30-40% as compared with KC 99(pheA tyrA trpE) containing recombinant plasmid pSC 101-trp operon. Activities of tryptophan synthase and production of tryptophan of KC 108 ($His^{-}$) and KC 109($Arg^{-}$) containing recombinant plasmid pSC 101-trp operon were increase by two-fold as compared with KC 107 containing pSC 101-trp operon.

• 미생물학회지
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• 제25권4호
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• pp.282-289
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• 1987

Pseudomonas putida KU816에서 분리한 플라스미드 pKU10의 여러가지 특성을 조사하고 그 제한 효소 지도를 작성하였다. pKU 10은 암펴설런, 테트라사이클린, 클로람페니콜에 대한 내성 유전자를 갖는 작은 R factor로서 마이토마이신 C에 의하여 큐어링 된다. 플라스미드의 크기는 9.4Kb로 측정되었다. pKU 10은 Pseudomonas와 E.coli블 숙주로 하였을 때 안정하게 형질 발현이 되다. 또한 pKU 10의 불화합성균은 IncP-I으로 조사되었다. Eco RI, Xho I. SaiI, BglII, SmaI은 pKU 10 DNA를 한 부위에서 자르고, Pst I은 두 부위, Hind Ill는 여섯 부위에서 자른다. 제한 효소 지도는 제한 효소를 이중, 삼중으로 완전 소화시키거나, 부분 소화시켜서 얻었다. pKU 10은 Pseudomonas속에서 유용한 클로닝 벡터호 이용된 것으로 기대된다.

• 미생물학회지
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• 제31권1호
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• pp.37-43
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• 1993

The effect of stb locus of E. COLI IncFII plasmid NR1 on the stability of chimeric plasmids was investigated. First, we have isolated the stability locus (stb) from E. coli NR1 plasmid and then inserted into the three different vectors, pUC8, YRp17 and YEp24. By examining their stability in E. coli and yeast, we showed that the recombinant plasmids containing stb locus were resonably stable. Also, by comparing the amounts of the rDNA fragments per haploid genome with those of the plasmid fragments, we showed they copy number of recombinant plasmids was not increased. Consequently, the stb locus of E. coli IncFII plasmid NR1 stabilized the chimeric plasmids but did not affect the replication or copy number of plasmids.