Judul: Peningkatan termostabilitas enzim alkalifilik xilanase dengan site directed mutagenesis
Abstrak: Application of xylanase in the pulp and paper industries required enzyme that is resistant to alkaline and high temperatures conditions. A suitable enzyme for that purpose is an alkalo-thermostable xylanase. The objective of this research is mutated gene alkxynaq1cmu by Site Directed Mutagenesis (SDM) method to increase thermostability of the xylanase. pGEMalkxynaq1cmu recombinant plasmids were mutated separately using 5 pairs of mutagenic primers, namely Q53K, Q62L, E146V, T194I, and S330I. Restriction result, 2 out of 5 mutated clones (2.2 and M3) has a XbaI restriction site that produce 3 DNA fragments. Mutan clones have xylanase activity that were varied from 22.7 U/ml to 49.3 U/ml. The results of sequencing from 3 clones showed 2 clones (2.2 & 3.9) contain a single nucleotide mutation and one clone (M3) contains a double nucleotides mutation. Clones 2.2 has successfully exchanged by Q62L primer that changed the amino acid glutamine to lysine, 3.9 clone has successfully exchanged by E146V primer, amino acid glutamic acid to valine, and M3 has successfully exchanged by E146V and Q62L primers.
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Judul: Mutasi Gen xyncmu dan Pengaruhnya terhadap Stabilitas Enzim Xilanase CMU dari Bacillus halodurans
Abstrak: Applications of xylanase enzyme on paper industry requires an enzyme characteristic through pH and resistant to high temperatures. A directed point mutations in site directed mutagenesis PCR which being the alternative to changing the enzyme’s characteristic and a several of amino acid on parental clon (M3) which effected with enzyme stability. This study aims to alter the stability of xylanase CMU and comparing the characters between CMU xylanase’s mutant and normal. The first step involves a plasmid with parental clones (Clone M3) which transferred to two pairs of mutagenic primers that Q53K and T194I. The amplicons from mutant plasmid pGEMalkxynaq1cmu M3 were transformed into Escherichia coli DH5α and selected with ampicillin media. Results of selection with ampicillin and restriction analysis were confirmed two positive mutant clones are Clone 4 and Clone 7 which brought of xyncmu gene. Gene mutation has succeeded to done as the result was Clone 7 which had enzyme’s characteristic through pH and resistant to high temperatures
Keyword: enzyme stability, CMU xylanase, xyncmu gene, Site directed mutagenesis

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular