Judul: Purification and characterization of thermostable chitinases from bacillus lichemiformis MB-2
Abstrak: Chitinases are of great biotechnological interest and have received remarkable attention. A themophilic bacterium, Bacillus lichenifomis MB-2, from Tompaso hot spring, North Sulawesi Indonesia, secreted thermostable chitinases into culture media. Preliminary study showed that the enzymes occur in multiple forms and were stable at a high temperature and a broad range of pH. The objectives of this research were to purify and characterize thermostable chitinases from B. lichenrformis MB-2. The extracellular chitinases were isolated by successive column chromatographies on Phenyl Sepharose CL4B, DEAE Sephacel, and Superdex G-75. The purified enzymes had molecular weight of 67 (Chi-67) and 102 kDa (Chi-102), estimated by SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). Chi-67 and Chi-102 had an endo- and exo- chitinolytic activities, respectively. The optimal temperature of Chi-67 was 70°C, whereas Chi-102 was 60 "C. The optimal pH for both enzymes was 6.0. Chi-67 wets stable below 60°C and over a broad pH range of 4-1 1 for 1 h. In contrast, Chi- 102 was not stable at temperature above 50 "C and only stable at its optimum pH for 1 h. Chi-47 was resistant to denaturation by urea, Tween-20 and Triton-X, but unstable toward organic solvents such as propanol, ethanol, DMSO (dimethyl sdfoxide), and PEG (polyethylene glycol), indicating that hydrophobic interaction of proteins plays an important role in maintaining enzyme activity. Ionic interactions are also important for Chi-67 fold as the activity was reduced by guanidine hydrochloride and NaCl (1 M). Chi- 1 02 was relatively more stable toward various organic solvents than Chi-67. Both enzymes hydrolyzed colloidal chitin, glycol chitin, or glycol chitosan, but were less active to regenerated chitin, fine powder of chitin, or methyl cellulose. The Michaelis constants &) for colloidal chitin, glycol chitin, 4- methylumbelliferyl N', W-diacetylchitobioside [MUF(GICNAC)~], 4- methyiumbelliferyl N', N', M-triacetylchitotrioside [MCTF(G~CNAC)f~o]r Chi-67 were 3.08 mg ml-', 0.3 15 mg ml-', 0.02 pmol d-' and 0.02 pmol dl, respectively. Meanwhile, the K, for colloidal chitin, glycol chitin and MUF(GlcNAc) for Chi-102 were 2.00 mg ml-', 1.32 rng ml-', and 0.03 mM ml-', respectively. The first 13 N-tertninal amino acids of Chi-67 were determined to be SGKNYKIIGYYPS, which is identical to chitinase from B. licImenIfomris PR- 1 (accession no. AA022 144) and B. circuImrs No. 4.1 (accession no. AM23 3 68).
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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: Performa Kuda Delman sebagai Alat Transportasi di Kota Bogor.
Abstrak: Kuda (Equus caballus) merupakan salah satu ternak yang sejak lama sudah memiliki hubungan dengan manusia. Peran kuda dalam kehidupan manusia dapat dilihat dari fungsinya sebagai mata pencaharin, alat transportasi, olahraga, dan sarana rekreasi. Delman merupakan salah satu alat transportasi tradisional di Kota Bogor yang memanfaatkan tenaga seekor kuda. Delman biasa digunakan untuk memindahkan orang dan barang dari satu tempat ke tempat lain. Kehadiran teknologi sekarang ini telah merubah peran dan fungsi delman dari alat transportasi atau pengangkutan menjadi alat untuk sarana rekreasi.
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