• Journal of Microbiology and Biotechnology
• /
• v.18 no.5
• /
• pp.815-820
• /
• 2008

Two culture-independent methods, namely ribosomal DNA libraries and denaturing gradient gel electrophoresis (DGGE), were adopted to examine the microbial community of a Malaysian light crude oil. In this study, both 16S and 18S rDNAs were PCR-amplified from bulk DNA of crude oil samples, cloned, and sequenced. Analyses of restriction fragment length polymorphism (RFLP) and phylogenetics clustered the 16S and 18S rDNA sequences into seven and six groups, respectively. The ribosomal DNA sequences obtained showed sequence similarity between 90 to 100% to those available in the GenBank database. The closest relatives documented for the 16S rDNAs include member species of Thermoincola and Rhodopseudomonas, whereas the closest fungal relatives include Acremonium, Ceriporiopsis, Xeromyces, Lecythophora, and Candida. Others were affiliated to uncultured bacteria and uncultured ascomycete. The 16S rDNA library demonstrated predomination by a single uncultured bacterial type by >80% relative abundance. The predomination was confirmed by DGGE analysis.

• The KIPS Transactions:PartB
• /
• v.10B no.7
• /
• pp.769-776
• /
• 2003

DNA computing has used to solve MCP (Maximal Clique Problem). However, when current DNA computing is applied to MCP. it can't efficiently express vertices and edges and it has a problem that can't look for solutions, by misusing wrong restriction enzyme. In this paper we proposed ACO (Algorithm for Code Optimization) that applies DNA coding method to DNA computing to solve MCP's problem. We applied ACO to MCP and as a result ACO could express DNA codes of variable lengths and generate codes without unnecessary vertices than Adleman's DNA computing algorithm could. In addition, compared to Adleman's DNA computing algorithm, ACO could get about four times as many as Adleman's final solutions by reducing search time and biological error rate by 15%.

• Journal of Microbiology and Biotechnology
• /
• v.6 no.2
• /
• pp.142-144
• /
• 1996

To clone the gene coding for steroid $\Delta^1$-dehydrogenase of Arthrobacter simplex, its genomic library was constructed with a , $\lambda$gt11 expression vector and immunoscreened with antiserum against the enzyme. One positive clone was found to carry a 1.6-kb EcoR I restriction endonuclease fragment of A. simplex DNA. The restriction map of the 1.6-kb EcoR I fragment was determined after cloning of the DNA into pBS vector.

• Journal of Microbiology and Biotechnology
• /
• v.2 no.1
• /
• pp.50-55
• /
• 1992

A genomic library of a mesophilic cellulolytic anaerobe, Clostridium sp. KCTC 8440 DNA was constructed in Escherichia coli using plasmid pUC9. Clones of E. coli exhibiting carboxymethyl cellulose-hydrolyzing activity (CMCase) were isolated and divided into seven types based on the restriction enzyme patterns of recombinant plasmids. E. coli strains carrying type A genes showed activity on carboxymethyl cellulose about 7-8 times greater than clones carrying genes of other types. Restriction maps of the cloned DNA fragments were determined, and homologies between them were investigated. The results suggest that Clostridium sp. KCTC 8440 has seven distinct CMCase genes.

• Biomedical Science Letters
• /
• v.8 no.2
• /
• pp.77-82
• /
• 2002

Ten Listeria monocytogenes were isolated from clinical specimens and mussels, and their physio-biochemical characters were compared with the type strains. Ribotyping was used as a taxonomic tool to determine molecular epidemiological marker. Chromosomal DNA was cleaved with restriction enzymes HindIII and EcoRI. The fragment were subjected to Southern blot hybridization with 165 rDNA from B. subtilis by PCR. EcoRI patterns of Listeria strains showed 6 to 8 bands ranging from 0.75 kb to 11 kb band and they were classified into 6 groups. In comparison, HindIII patterns revealed that 5 to 7 bands ranging from 2.75 kb to 7.75 kb band and they classified into 5 groups. The various patterns of Listeria strains were observed within genus, species and isolated sources. 165 rRNA gene restriction patterns (ribotyping) are useful in epidemiological and taxonomic study.

• Journal of Microbiology
• /
• v.39 no.4
• /
• pp.265-272
• /
• 2001

Variation within the intergenic spacer(IGS) of the ribosomal DNA gene for twenty-two strains of E. oxysporum and its formae speciales was examined by PCR, couped with RELP analysis. The length of the amplified IGS region was about 2.6 kb in all strains except F.oxysporum f. sp. cucumer-inum from Korea and F. oxysporum f. sp. niveum. Those two strains were 2.5 kb long. Restriction digestion of IGS-RELP regions by Eco RI, NruI, HincII, SAlI, SmaI, BalIi, HindIII, XhoI and KpnI gave rise to nine IGS hapoltypes among all strains. Cluster analysis based on the presence of absence of comigrating restriction reagments show the two groups based on 44% genetic similarity. These results demonstrated that analysis of IGS showed some difference within and between F. oxysporum formae speciales.

• Journal of Microbiology
• /
• v.34 no.1
• /
• pp.1-6
• /
• 1996

The nucleic acid of Synechococcus sp. cyanophage was identified as double-stranded DNA by the result of digestion with enzymes such as exonucleases, DNase, and S1 nuclease, and by acridine orange staining. The cyanophage DNA was cleaved with several restriciton ehdonucleases such as ApaI, BamHI, Bg/II, HaeIII, Eco RI, HindIII, PstI, AND aPAI gave the clearest sets of bands on agarose gels and the fragment numbers for each were 12, 20, 29, 20, and 7, respectively. The sums of the size from Bam HI and PstI digestions were estimated approximately 227$\pm$4 kb, which are in agreement with the result of the pulsed field gel electrphoresis. This virus is thought to have the largest genosome among those of known cyanophages, which corresponds to the largest haed ot 90 nm when compared with the head sizes of cyanophages discovered since 1963.

• Journal of Ginseng Research
• /
• v.19 no.1
• /
• pp.51-55
• /
• 1995

The DNA fragment containing ginseng ribulose-1,5-bisphosphate carboxytase/oxygenase large subunit(rbcL) gene was cloned from the ginseng chloroplast EcoRl library by colony lift hybridization with tobacco rbcL gene probe. From the screened clone, the DNA fragment containing ginseng rbcL gene was digested with several restriction enzyme and analyzed by Southern blot hybridization for the construction of restriction map. The ginseng rbcL gene fragment was subcloned in pBluescript II SK + vector and sequence analysis was performed. The nucleotide sequence of ginseng rbcL gene was compared with those of petunia, tobacco, alfalfa, rice and barley, which showed a homology of 93.1%, 95.2%, 90.5%, 85.5% and 84.3%, respectively.

• Journal of Sericultural and Entomological Science
• /
• v.37 no.1
• /
• pp.16-26
• /
• 1995

DNA restriction fragment length polymorphisms(RFLPs) were used for the classification of 22 leading silkworm races and wild silkworm, Bombyx mandarina. A genomic DNA library from silkworm was partially constructed and was prescreened to evaluate the selected DNA probes. Three DNA probes (SP1-13, SP1-28, 10-42) were selected to determine the polymorphism between silkworm races. As a result, high polymorphism with the probe SP1-28, moderate polymorphism with SP1-13 and monomorphism with 10-42 were obse-rbed.

• Korean Journal of Microbiology
• /
• v.24 no.2
• /
• pp.86-90
• /
• 1986

The DNA methylated by Hpa II methylase was not cleaved by Sma, I, Ava I and Nae I endonucleases. This experimental data could be interpreted as strong evidences that Sma I, Ava I and Nae I methylases which yet to be isolated would methylate on the inmost cytosine nucleotide within their hexameric recognition sequences. The facts that Sma I, Ava I and Nae I endonucleases can not cleave the DNA methylated by Hpa II methylase are the valuable informations for protecting DNAs upon cleavage reactions by Sma I, Ava I and NAe I endonucleases especially for cDNA insertion experiments into vector DNAs using Sma I, Ava I and Nae I oligonucleotide linkers. In the case of Xma I endonuclease, partially cleaved DNA fragments were observed although the reaction rate was greatly decreased. This result implies that the methylation site of Xma I methylase which yet to be isolated would not be the same as that of Hpa II methylase in Xma I sequence.