Journal of Microbiology

Bae, Kyung Sook

6 Articles

Identification and Characterization of an Oil-degrading Yeast, Yarrowia lipolytica 180: Kim, Tae Hyun+ , Lee, Jung-Hyun , Oh, Young Sook , Bae, Kyung Sook , Kim, Sang Jin; J. Microbiol. 1999;37(3):128-135.

Abstract PDF: Among oil-degrading microorganisms isolated from oil-polluted industrial areas, one yeast strain showed high degradation activity of aliphatic hydrocarbons. From the analyses of 18S rRNA sequences, fatty acid, coenzyme Q system, G+C content of DNA, and biochemical characteristics, the strain was identified as Yarrowia lipolytica 180. Y. lipolytica 180 degraded 94% of aliphatic hydrocarbons in minimal salts medium containing 0.2% (v/v) of Arabian light crude oil within 3 days at 25℃. Optimal growth conditions for temperature, pH, NaCl concentration, and crude oil concentration were 30℃, pH 5-7, 1%, and 2% (v/v), respectively. Y. lipolytica 180 reduced surface tension when cultured on hydrocarbon substrates (1%, v/v), and the measured values of the surface tension were in the range of 51 to 57 dynes/cm. Both the cell free culture broth and cell debris of Y. lipolytica 180 were capable of emulsifying 2% (v/v) crude oil by itself. They were also capable of degrading crude oil (2%). The strain showed a cell surface hydrophobicity higher than 90%, which did not require hydrocarbon substrates for its induction. These results suggest that Y. lipolytica has high oil-degrading activity through its high emulsifying activity and cell hydrophobicity, and further indicate that the cell surface is responsible for the metabolism of aliphatic hydrocarbons.

Phylogenetic study of penicillium chrysogenum based on the amino acid sequence analysis of chitin synthase: Park, Bum Chan , Lee, Dong Hun , Bae, Kyung Sook , Park, Hee Moon; J. Microbiol. 1997;35(3):159-164.

Abstract PDF: The phylogenetic study of Penicilium chrysogenum was performed based on amino acid sequence comparison of chitin synthase. Phylogenetic trees were constructed with the deduced amino acid sequences of the highly conserved region of chitin synthase gene fragments amplified by PCR. The BlasP similarity search and the bootstrap analysis of the deduced amino acid sequences of chitin synthase from P. chrysogenum with those form other fungi showed a close evolutionary relationship of Penicillium to ascomycetous fungi, especially to genus Aspergilus. The result from bootstrap analysis of the deduced amino acid sequences of the Class II chitin synthase from ascomyceteous fungi supported the usefulness of the Class II chitin synthease for phylogenetic study of filamentous fungi.

Cloning and phylogenetic analysis of chitin synthase gene from entomopathogenic fungus, beauveria brongniartii: Nam, Jin Sik , Lee, Dong Hun , Park, Ho Yong , Bae, Kyung Sook; J. Microbiol. 1997;35(3):222-227.

Abstract PDF: DNA fragments homologous to chitin synthase gene were amplified from the genomic DNA of Beauveria brongniartii by PCR using degenerate primers. Cloning and sequencing of the PCR-amplified fragments led to the identification of a gene, designated BbCHS1. Comparison of the deduced amino acid sequence of BbCHS1 with those of other Euacomycetes revealed that quence of BbCHS1 displayed the highest rate of similarity, 95.8%, with CHS2 or Metarhizium anisopliae. Phylogenetic analysis of the amino acid sequences confirmed the taxonomic and evolutionary position of B. brongiartii, which was previously derived by traditional fungel clasification based on morphological features.

Phylogenetic relationship of ganoderma species with the polyporaceae base don RFLP analysis of the nuclear ITS region: Park, Hong Je , Shin, Kee Sun , Yoon, Cheol Sik , Lee, Dong Hun , Bae, Kyung Sook; J. Microbiol. 1996;34(2):117-123.

Abstract PDF: Restriction-polymorphic patterns of nuclear-ITS were examined for the genetic relationships among 12 bisidiomycetous mushrooms to Aphyllophorales and Agaricales. The taxonomic affinity of Ganoderma species with the family Polyporaceae also was examined. With 13 restriction endonucleases, 159 restriction characters were generated form the 12 species examined. UPGMA and neighbor-joining analyses separated the 12 species into two genetically distinct groups that correspond to orders (Agaricales and Aphyllophorales) where each species is included. This result indicates that there is clear genetic demarcation between Agaricales and Aphyllophorales. Dendrograms constructed by several data analyses showed that even though Ganoderma species are somewhat in intermediate taxonomic position between the Polyporaceae and families of the Agaricales, they are genetically more related to the Polyporaceae. These results are consistent with morphological characters observed in those mushrooms. However, it is premature to conclude taxonomic status Ganoderma species in the present study employing small sample size.

Genetic Relationships among Penicillium Species by Characterizing RAPD Markers: Yoon, Cheol Sik , Bae, Kyung Sook; J. Microbiol. 1995;33(3):171-177.

Abstract PDF: Random amplified polymorphic DAN markers were characterized for three taxonomically problematic Penicillium species : P. aurantiogriseum var. Aurantiogriseum, P. verrucosum and P. puberulum, as well as for 25 species of mono, bi-, and terverticillate Penicillia. The relationships among mono, bi-, and terverticillate Penicillium species were determined from these RAPD markers. Eight species from mono-, eight from bi-, and nine from terverticilate Penicillia were examined. With 14 randomly chosen 10-mer primes, a 310 character by 25 species matrix was generated. Phenetic analysis separated the 25 species into three genetically distinct groups that correspond to the different arrangements of penicilli (mono-, bi-, and terverticillate). The results of this study suggest that P. aurantiogriseum var. aurantiogriseum, P. VERRUCOSUM, AND P. puberulum represent genetically distinct species, and that P. vulpinum should be included in terverticilate Penicillia. Phenogram branching patterns indicated that biverticillate species are genetically more similar to monoverticilate species than they are to terverticillate species.

Biosynthesis of Poly-β-Hydrozyalkanoates by Bacillus thuringiensis R-510: Lee, Kang Tae , Kim, Jeong Yoon , Rhee, young Ha , Bae, Kyung Sook , Kim, Young Baek; J. Microbiol. 1995;33(1):59-65.

Abstract PDF: Synthesis and accumulation of Poly-β-Hydrozyalkanoates (PHA) in Bacillus thuringiensis R-510 isolated from soil were investigatd. This organism was resistant to relatively higj concentration of propionate and had a capability of accumulatinf copolymers consisting of 3-hydroxybutyrate(3HB) and 3-hydroxyvalerate(3HV) when the medium was supplemented with propionate as a precursor, The PHA content maximally reached up to 44.5% of dry cell weight in the presence of 0.1% propionate. The molar fraction of 3HV in the copolymer was increased from 19.4 to 80,2 mol% by adding 0.05 to 0.5% propionate to glucose medium. The addition of propionate during exponential or stationary phase of cell growth was less effective for the enhancement of 3HV content in the copolymer, although cell mass and PHA content were not affected by the time of propionate addition. PHB homopolymer and copolymer produced by B. thuringiensis R-510 were measured to have number average molecular weights in the range of 53,000 to 65,000. Polydispersity indices were between 1.5 and 2.2. Some of the produced polymers had bimodal molecular weight distribution.

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