Judul: Analisis Sekuens Gen Penyandi Enzim Xilanase Ekstraseluler pada Streptomyces costaricanus 45I-3
Abstrak: Streptomyces costaricanus 45I-3 isolated from peat soil is a bacterial strain in the group of actinomycetes. This bacterium is known to produce extracellular xylanase. The objectives of this study were to analyze sequence of gene involved in the synthesis of extracellular xylanase. Complete gene encoding xylanase was isolated from the bacterial genome by Inverse Polymerase Chain Reaction (i-PCR). The resulted gene sequence in a total alignment of 1664 bp amplicons, which consisted of two open reading frame (ORF) with opposite direction. ORF1 consisted of 1029 bp and ORF2 (Partial sequence) consisted of 309 bp. BLASTX analysis showed ORF1 homology with xylanase of bacterium enrichment culture clone Xyl8B8 (GenBank accession No. AFH35005.1) that had 95% identity and 99% similarity. ORF2 homolog with glyoxalase bacterium enrichment culture clone Xyl8B8 (GenBank accession No. AFH35007.1) that had 95% identity and 98% similarity. Upstream of the ORF1 sequence was found Ribosome Binding Site (RBS) 7 bp from the start codon and putative promotor sequence at 100 bp (-35) and 77 bp (-10) from the start codon. Analysis of protein sequence deduced from ORF1 showed that there were 2 domains, i.e Glyco_hydrolase 11 (GH11) and Carbohydrate Binding Type 2 (CBM2). Active sites found on the 130 amino acid on GH11 domain. Visualization of 3 dimension structure showed that 1664 bp fragment had 19 area.
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Judul: Kloning Gen Xilanase Termozim Dari Streptomyces costaricanus 45I-3
Abstrak: Biopolymer xylan has a great potential to produce useful end product such as xylose. Xylanases is a group of enzyme that has ability to hydrolyse xylan or polymer of xyloses and xylooligosaccharides. Complete hydrolysis of xylans involves the synergistic action of a xylanolytic enzymes, including ß-xylanase, ß-xylosidase, -glucuronidase, -L-arabinofuranosidase, and acetyl xylan esterase. The aims of this research were to isolate xylanase gene from Streptomyces costaricanus 45I-3 and to clone this gene into competence Escherichia coli DH5 . Genomic DNA was obtained from S. costaricanus 45I-3 that have known has ability to produce thermostabile extracellular xylanase. Genomic DNA was partially digested with restriction enzyme Sau3A1. Genomic DNA fragments of size 4-10 kb were inserted at BamHI site in pBluescript II KS (+) vector and transformed into E. coli DH5 . Based on blue-white selection approximately 12000 recombinant colonies were obtained. The presence of xylanase gene was identified by screening employing congored plate clearance assay. One positive clone containing the xylanase gene was confirmed and was designated as pHS11. Preliminary characterization of pHS11 using EcoRI showed that it contained a 6,0 kb DNA insert. Xylanase were produced has xylanase spesific activity 6,393 U/mg, -xylosidase activity 0,208 U/ml, arabinofuranosidase activity 0,079 U/ml and acetyl xylan esterase activity 0,063 U/ml as well.
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Judul: Aplikasi Temu-Kembali Poligon Berdasarkan Kemiripan Bentuk
Abstrak: Rerrieval basis data gambar tidak efektif bila dilakuktm dengan menggunakan keyword seperti layaknya retrieval basis data leks. Hal ini disebabkan gambar tidak efektif diwakili oleh keyword. Metode yang efektif bagi retrieval gambar adalah retrieval berdasarkan kemiripan. Retrieval ini diharapkan konsisten dengan penglihatan mata manusia, yang diperoleh melalui penghitungan uknran kemiripan tertentu.
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