Judul: Purifikasi Parsial dan Karakterisasi Enzim Protease dari Isolat B19 KUB BPPT CC
Abstrak: The inability of the plant and animal proteases to meet current world demands has led to an increased interest in microbial proteases. The purpose of this research was to purify and characterize microbial protease from B19 KUB BPPT CC isolate. The isolate were grown in media containing calcium caseinate agar 0.5%, urea 0.5%, and yeast extract 0.05%. Extracelluler protease from B19 KUB BPPT CC isolate was purified using amonium sulfate precipitation and dialysis. The protease was purified 8.37 fold with a recovery by 60% amonium sulfate precipitation. This thermophilic alkaline protease showed a pH optimum of 9.0 and optimum temperature was 60 °C. Phenylmethanesulfonyl-fluoride (PMSF) completely inhibited the enzyme activity suggesting that it was serine protease. Among metal ions, the Na+ ions enhanced activity up to 119.93%. The Km and Vmax values exhibited by purified protease were 0.021 mM and 90.91 U/mgusing casein as substrate. The molecular weight was estimated to be 33.8 kDa and 19.7 kDa on casein zymography. In addition, this enzyme was capable of hydrolyzing bovine serum albumin (BSA), gelatin, hemoglobin, casein, and collagen
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Judul: Isolasi, Pemurnian Parsial, dan Karakterisasi Enzim Kitinase dari Bacillus sp. BPPT CC 2
Abstrak: Chitinase is a potential enzyme due to its acitvity hydrolyting chitin to its derivates. Therefore, it can be used for various applications, such as agriculture, microbiology, and cosmetic. This study aimed to isolate, purify, and characterize (pH, temperature, metal ion effect, molecular weight, and kinetic parameters) chitinase of Bacillus sp. BPPT CC 2. Ammonium sulphate precipitation and dialysis were used for enzyme purification. Enzyme was characaterized its optimum pH and temperature, metal ions, molecular weight, as well as kinetic parameters. The results showed that enzyme was well precipitated using 80% ammonium sulphate. After dialyzed, level of enzyme purity increased 6.58 fold with specific activity of 0.0924 U/mg. Results showed that the optimum temperature and pH of chitinase were found at 55ºC and pH 5. Value of Km and Vmaks values were 2.705x10-4mg/L second and 0.6959 mg/L. Predicted molecular weight of chitinase was 103 kDa. Addition of metal ions Mn2+and EDTA (5 mM and 10 mM) act as activators of chitinase
Keyword: Bacillus sp. BPPT CC 2, characterize, chitinase, kinetic parameter, purification

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