• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.52-58
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• 1987

The yeast S. cerevisiae DBY747 was transformed with E. C - S. C shuttle vector YIp5, YEp13 and YRp7 by the method of spheroplast. The transformation frequency of YEp13 and YRp7 in S. cerevisiae DBY747 was $1.2{\times}10^3$ and $1.0{\times}10^2$ per $10{\mu}g$ of DNA, respectively. The transformants with YIp5 plasmid incapable of autonomous replication in S. cerevisiae were not detected in the condition of this experiment, but YIpS plasmid expressed the gene carried on it when cotransformed with a helper plasmid such as YEp13 or YRp7 : autonomously replicating plasmid. When plasmids were used in covalently closed circular form, cotransformation frequency of Ylp5-YEpl3 and Ylp5-YRp7 was 210 and 95 per $10{\mu}g$ of DNA, respectively. In cotransformation of linear plasmids, transformation frequency of the same cohesive ends was similar to that of noncomplementary cohesive ends. Transformants by the cotransformation with circular plasmids have been shown much higher frequency than with linear plasmids in S. cerevisiae DBY 747. The mitotic segregation stability test suggested that the cotransformant of YIpS-YEp13 was more stable than that of YIpS-YRp7.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.141-147
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• 1993

Plasmid DNAs were detected from the mitochondrial fraction of four strains of whiterot fungus, Pleurotus ostreatus. The size of the plasmids were 10.2 and 7.2 kb in strain NFFA 2, 10.2 kb in NFFA 4001, 11.2 kb in NFFA 4501, and 10.2 and 11.2 kb in KFCC 11635. The two strains,NFFA 2ml and NFFA 2m2, which are mutant derivatives of NFFA 2, did not contain any plasmids. The cleavage by proteinase K indicated that these plasmids have DNA ends associated with proteins. In digestion with proteinase K all the plasm ids remained resistant to lambda exonuclease which hydrolyzes DNA from 5' ends and were sensitive to exonuclease III which hydrolyzes DNA from 3' ends. This suggests that the plasmids are linear double-stranded DNA and the terminal proteins are covalently linked to 5' ends of plasm ids. In order to find relationship between these plasmids, hybridization of plasm ids by each separate plasmid DNA was done. The result indicated that the plasmids can be classified into at least 3 groups. Plasmids of group I were present in all the P ostreatus. More mitochondrial plasmids were detected in P cornucopiae. P ,florida, P pulmonarius, P sajor-caju, and P spodoleucus. The size of plasmids ranged between 7.2 kb and 14 kb. All the species except P cornucopiae contained plasmids of approximately 10 kb which hybridized with the 10.2 kb plasmid (group I) of P ostreatus NFFA 2.

• Journal of Life Science
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• v.2 no.1
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• pp.26-34
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• 1992

유전자 재조합 균주의 발효에 있어서 플라스미드의 안정성과 발효공정의 최적화에 대해 개략적으로 서술하였다. 클론된 DNA의 발현은 플라스미드의 안정성을 크게 저해하며, 저하된 플라스미드의 안정성은 재조합 균주의 생산성을 많이 떨어뜨린다. 최적 발효 조건은 각각의 숙주-벡터 시스템, 사용한 배지, 생성물 등에 따라 크게 변한다. 동일한 숙주-벡터 시스템의 경우도, 사용하는 배지에 따라 온도, 희석률 또는 성장속도에 의존하는 정도가 달라지고 또 최적값도 다 변한다. 또한 발효조건의 최적화가 균체 내 플라스미드의 자기복제,mRNA로의 전사, 단백질로의 translation, 더 나아가 미생물 전체의 생리와 밀접하게 관련이 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.4
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• pp.1000-1006
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• 2011

We examined the effects of various phenolic compounds, Ti plasmids(octopine, nopaline) and A. tumefaciens on the vir gene expression. Nine phenolic compounds were tested using 3 types of Ti plasmid and 3 strains of A. tumefaciens on the vir gene expression. It was also investigated how the levels of vir gene expression could be related to specific phenolic compounds. Six phenolic compounds as 4-hydroxyacetophenone, phenol, catechol, resorcinol, acetosyringone and vanillin had exhibited a strong effect on the vir gene expression of A. tumefaciens MW107 containing nopaline Ti plasmid. The vir genes of A. tumefaciens MW105 and MW108 containing octopine Ti plasmids were remarkably stimulated only by acetosyringone. Thus, it appeared that the vir gene inducing abilities were differed by the kinds of phenolic compounds, A. tumefaciens and Ti plasmids.

• Microbiology and Biotechnology Letters
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• v.17 no.1
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• pp.51-55
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• 1989

The conjugally transferred TOL plasmid or NAH plasmid was stably maintained and expressed in n-alkane assimilating Pseudomonas putida KCTC 2405. However, these plasmids were not able to coexist in this strain because of incompatibility. The incompatibility of TOL and NAH plasmid was bypassed using CAM::TOL* plasmid, which was constructed by the transposition of only tol gene without incompatibility system in TOL plasmid into CAM plasmid. p. putida 3SK capable of growing on m-toluate, naphthalene, camphor, and n-alkane(C8-C24) was constructed by the conjugal transfer of NAH plasmid into n-alkane assimilating p. putida SK carrying CAM:: TOL* plasmid. CAM::TOL＊ plasmid in p. putida 3SK was stable on the selective media but unstable on the nonselective media.

• Korean Journal of Microbiology
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• v.37 no.1
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• pp.37-41
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• 2001

Two linear plasmid-like DNAs, 10.2 kb and 7.2 kb were found in the mitochondria of P. ostreatus. They have covalently linked 5'-terminal proteins in both ends. Two continuous fragments of 4.7 kb and 2.3 kb from 7.2 kb DNA were cloned and sequenced. Two long open reading frames (ORF1; 2982 bp, 993 a.a and ORF2; 2703 bp, 900 a.a) and one short open reading frame(ORF3; 771 bp, 256 a.a) were found in the 7.2 kb plasmid. The putative ORF1 and ORF2 have conserved motifs of DNA polymerases and RNA polymerases, respectively, while the ORF3 has homologous regions with phosphatase from Plasmodium, and also with adhesine from Mycoplasma.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.165-169
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• 1997

Two gentamicin resistance R plasmids, pGM5 and pGM6, containing aacC2 gene were selected from environmental isolates. The gentamicin resistance determinants of R plasmids were cloned into the BamHI site of pUC18. Restriction enzyme map of inserted region of recombinant plasmids, pSYS and pSY6, and PCR results indicated that Tn3 sequence was located upstream of gentamicin resistance gene. Based on the restriction maps and susceptibility tests, it was concluded that the sequence of bla and 3' inverted repeat of Tn3 play a important roles in the expression of gentamicin resistance gene.

• Microbiology and Biotechnology Letters
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• v.17 no.4
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• pp.321-326
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• 1989

Eighty two bacterial strains have been isolated from five different soil and sewage samples by selective enrichment culture on m-toluate minimal medium. Two of these were identified as Pseudomonas capacia, one as P. putida, one as Yersinia intermedia, and one as Flavobaeterium odoratum. P. cepacia SUB37 appeared to carry plasmid superficially similar to TOL plasmid previously described in p. putida mt-2 and other two plasmids from Flavobacterium odorutum and Y. intermedia larger than that of p. putida mt-2. p. cepacia SUB37 was sensitive to streptomycin but resistant to rifampicin. P. cepacia SUB37 carrying plasmid metabolizes the hydrocarbons to benzoate and toluates via the corresponding alcohols and aldehydes. By the curing experiment, it appears that P. cepacia SUB37 carries TOL plasmid encoding for the enzymes responsible for the catabolism of toluene and xylene via benzoate and the toluates and then by meta pathway in the process of degradation of aromatic hydrocarbons. p. cepacia SUB37 degraded m-toluate rapidly to be very low level when it was fully grown.

• Korean Journal of Microbiology
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• v.23 no.1
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• pp.56-63
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• 1985

We have characterized the plasmids of zymomonas, and constructed E. coli-Zymomonas shuttle vector. Plasmids have been detected in four strains of Zymomonas mobilis. All strains tested had at least one plasmid ranging in size from about 1.7 to 46kb. Antibiotics resistances of Z. mobilis were tested to select the host strain. All strains were very sensitive to tetracycline and chloramphenicol. Homology tests between the plasmids in four strains showed that the plasmids of ATCC10988 is highly homologous to those of ZM1, and that there is no homology between plasmids of ZM4 and Agll. The 1.7kb plasmid of ATCC10988, named as pZM886, also has no homology with plasmids of ZM4. A hybrid plasmid, designated to pBZ41, was constructed from pZM886 and pBR322. A restriction map of pBZ41 was established. Replicon of pZM886 didn't operate in E.coli and pBR322 seemed not to replicate in Zymomonas. pBZ41 was transfered from E. coli to Zymomonas by conjugal mobilization. The transconjugants were resistant to tetracycline and maintained pBZ41 stably.

• Korean Journal of Microbiology
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• v.24 no.1
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• pp.7-11
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• 1986

We screened lysates of the laboratory strains of pseudomonads utilizing hydrocarbon by agarose gel electrophoresis and cesium chloride-ethidium bromide equilibrium centrifugation, to find an intrinsic plasmid as a vector and to examine the relationship between the plasmid and hydrocarbon degradation. Only one strain from the examined strains, Pseudomonas putida KU190, contained a plasmid. We named the plasmid pKU41. The molecular size of pKU41 was determined as 41kb, using covalently closed circular forms of RP4 and pSY343 as standard size markers. The restriction sites of pKU41 for BamHI, BglII, EcoRI, HindIII, and SalI were 3, 1, 3, 6 and more than 13, respectively. With double or triple digestion, restriction map of pKU41 was constructed for BamHI, BglII and HindIII. For elucidation on the biological function of the plasmid, test was conducted on the ability of hydrocarbon utilization of the host strain but no apparent relationship was observed.