• Journal of Microbiology
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• 제45권5호
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• pp.409-417
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• 2007

Burkholderia sp. HY-10 isolated from the digestive tracts of the longicorn beetle, Prionus insularis, produced an extracellular lipase with a molecular weight of 33.5 kDa estimated by SDS-PAGE. The lipase was purified from the culture supernatant to near electrophoretic homogenity by a one-step adsorption-desorption procedure using a polypropylene matrix followed by a concentration step. The purified lipase exhibited highest activities at pH 8.5 and $60^{\circ}C$. A broad range of lipase substrates, from $C_4\;to\;C_{18}$ p-nitrophenyl esters, were hydrolyzed efficiently by the lipase. The most efficient substrate was p-nitrophenyl caproate ($C_6$). A 2485 bp DNA fragment was isolated by PCR amplification and chromosomal walking which encoded two polypeptides of 364 and 346 amino acids, identified as a lipase and a lipase foldase, respectively. The N-terminal amino acid sequence of the purified lipase and nucleotide sequence analysis predicted that the precursor lipase was proteolytically modified through the secretion step and produced a catalytically active 33.5 kDa protein. The deduced amino acid sequence for the lipase shared extensive similarity with those of the lipase family 1.2 of lipases from other bacteria. The deduced amino acid sequence contained two Cystein residues forming a disulfide bond in the molecule and three, well-conserved amino acid residues, $Ser^{131},\;His^{330},\;and\;Asp^{308}$, which composed the catalytic triad of the enzyme.

• 한국응용곤충학회지
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• 제46권1호
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• pp.131-139
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• 2007

곤충으로부터 유용 효소생산 미생물의 탐색 과정에서 우수한 lipase 생산균주 9종을 분리하고 lipase 생산능을 조사하였다 16S rDNA 분석 결과 분리된 균주는 주로 Serratia 속, Pseudomonas 속, Burkholderia 속에 속하는 그람음성균들로 분석되었다. 그 중 lipase 생산능이 가장 우수한 균주를 선별하고 16S rDNA 서열분석 및 생리 생화학적 분석 결과를 바탕으로 Burkholderia sp. HY-10으로 동정하였으며 균주의 lipase생산특성을 조사하였다. 이 균주는 톱하늘소의 장으로부터 분리되었으며 olive oil을 탄소원으로 포함하는 배지에서 배양하였을 때 세포밀도에 의존하여 lipase의 생산이 유도되는 특성을 나타내었고 0.5%의 yeast extract와 0.5%의 olive oil이 포함된 M9배지에서 $30^{\circ}C$, 36-42시간의 배양에 의해 lipase의 생산이 최대치에 도달하였다.

• International Journal of Industrial Entomology and Biomaterials
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• 제2권1호
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• pp.37-53
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• 2001

Two regions of mtDNA genome, cytochrome oxidase subunit I (COI) and 165 ribosomal RNA (165 rRNA) genes, were sequenced for 15 species of the long-horned beetle belonging to four subfamilies and geographic samples of mulberry longicorn beetle, Apriona germari, from two localities in Korea. Ten samples of A. germari collected from Suwon and Busan revealed three COI haplotypes ranging in nucleotide divergence of 0.3% to 0.5%, and the two populations shared one common COI haplotype (80%). The sequence divergence among 15 species of the long-horned beetle was much higher in COI gene (12.3%∼39.4%) than 16S rRNA gene (7.2% to 23.1), and the maximum value in the COI gene is exceptional compared with other relevant studies, including that of Coleoptera. The greatly increased divergence in the COI gene, in facto was stemmed from a peculiar sequence of Prionus insularis belonging to Prioninne, divergence of which ranges from 31.2% to 39.3% from other species. We discussed possible reason of the divergence in this species. Due to the abnormality of COI gene divergence, decrease in phylogenetic signal was severe in COI nucleotide and, subsequently, the converted amino acid sequences, rendering us to put more confidence on the 16S5 rRNA gene data. Although the molecular phylogeny confidently supports the monophyletic origin of Lepturinae, the presence of discrepancy between molecular data and traditional taxonomic views also is a testable hyothesis. One such discrepancy includes taxonomic position of Sophronica obrioides and Theophilea cylindricollis belonging to Lamiinae.