Judul: Characterization of Lactic Acid Bacteria Isolated from Sumatran Orangutan (Pongo abelii) as Probiotic Candidate
Abstrak: Penggunaan probiotik sebagai alternatif dari antibiotik saat ini mulai dikembangkan karena mampu memberikan keuntungan bagi kesehatan orang utan. Probiotik yang tergolong sebagai Bakteri Asam Laktat (BAL) mampu menjadi antioksidan, antikanker, imunomodulator, serta antiinflamasi. Penelitian ini bertujuan mengidentifikasi dan karakterisasi BAL pada orang utan sumatra (Pongo abelii) sebagai kandidat probiotik. Sampel yang digunakan berasal dari masing-masing 5 feses orang utan sumatra Taman Nasional Gunung Leuser dan Taman Safari Indonesia. Feses diinokulasikan pada media selektif MRSA (de Man Rogosa Sharpe Agar). Koloni-koloni yang tumbuh lalu dimurnikan. Koloni tumbuh lalu diidentifikasi melalui pewarnaan Gram dan uji biokimia. Koloni teridentifikasi BAL dilakukan karakterisasi probiotik mencakup uji ketahanan garam NaCl (NaCl 2%, 4%, dan 6,5%), uji ketahanan pH (pH 2 dan pH 3), serta uji ketahanan garam empedu (MRS Bile Salt Broth 0,3% dan 1%). Hasil penelitian menunjukkan dari 28 isolat teridentifikasi jenis bakteri sebanyak 26 isolat. Sebanyak 22 isolat BAL dilanjutkan untuk pengujian karakterisasi probiotik. Hasil karakterisasi pada 22 isolat BAL menunjukkan sebanyak 12 isolat, mencakup 6 genus yang mengarah spesifik pada 8 spesies, memiliki karakter sebagai kandidat probiotik yakni Macrococcus sp., Lactobacillus sp., Streptococcus sp., Weissella sp., Pediococcus sp., dan Aerococcus spp. Sebanyak 10 isolat lainnya berpotensi sebagai probiotik namun perlu ditinjau kembali., The use of probiotics as an alternative to antibiotics is currently being developed due to their benefits to orangutans’ health. Probiotic bacteria classified as Lactic Acid Bacteria (LAB) are capable of being antioxidants, anticancer, immunomodulators, and anti-inflammatories. This study aims to identify and characterize LAB in Sumatran orangutan (Pongo abelii) as probiotic candidates. The samples used are from the feces of each 5 individuals of Sumatran orangutans from Taman Safari Indonesia and Gunung Leuser National Park. The feces inoculated to a selective media MRSA (de Man Rogosa Sharpe Agar). The growing colonies were then purified on a separate MRSA and then incubated. Growing colonies were identified through Gram staining and biochemistry test. Colonies identified as LAB were then subjected to probiotic characterization including NaCl salt resistance tests (NaCl 2%, 4%, and 6.5%), pH resistance tests (pH 2 and pH 3), and bile salt resistance tests (MRS Bile Salt Broth 0, 3% and 1%). The results showed that from 28 isolates, 26 of them is identified into species of bacteria. The amount of 22 isolates identified as LAB then were continued to the probiotic characterization test. The characterization results showed the 12 isolates, which consist of 6 genus that specifically led to 8 species, presented the probiotic candidate characters which were Macrococcus sp., Lactobacillus sp., Streptococcus sp., Weissella sp., Pediococcus sp., and Aerococcus spp. Other 10 isolates were also potential as probiotics but needed to be reviewed.
Keyword: lactic acid bacteria, Pongo abelii, probiotic, sumatran orangutan

Judul: Identification and Total of Lactic Acid Fermentative Bacteria in Primate Feces
Abstrak: Bakteri asam laktat (BAL) bermanfaat bagi kesehatan, terutama peranannya sebagai probiotik dan antimikroba dalam pengobatan penyakit saluran pencernaan pada primata. Penelitian ini bertujuan untuk mengidentifikasi serta menghitung total koloni bakteri asam laktat pada feses lima jenis primata yaitu orang utan, owaungko hitam, owa ungko coklat, siamang, dan lutung yang dikoleksi dari Kebun Binatang Bukittinggi. Sampel dilakukan pengenceran 10-1 hingga ke 10-7 dandiinokulasikan ke dalam media selektif MRSA (de Man Rogosa Sharpe Agar) dengan metode pour plate. Koloni bakteri asam laktat yang tumbuh pada media diamati dan dihitung total koloninya. Koloni terpilih diisolasi untuk selanjutnya diidentifikasi menggunakan beberapa uji biokimia yaitu uji katalase, uji oksidase, uji Sulfide Indol Motility, uji Methyl Red-Voges Proskauer, dan uji fermentasi karbohidrat. Penelitian berhasil mengisolasi bakteri dari genus Lactobacillus, Leuconostoc, dan Weissella. Hasil penelitian menunjukkan orang utan menghasilkan total bakteri asam laktat tertinggi yaitu sebesar 3,1 x 108 CFU/ml., Lactic acid bacteria (LAB) are beneficial for health, especially their role as probiotics and antimicrobials in the treatment of digestive tract diseases in primates. This research aims to identify and count the total colonies of lactic acid bacteria in the feces of five primate species, namely orangutans, black gibbons, brown gibbons, siamang, and langurs collected from the Bukittinggi Zoo. Samples were diluted 10- 1 to 10-7 and inoculated into MRSA (de Man Rogosa Sharpe Agar) selective media using the pour plate method. Colonies of lactic acid bacteria growing on the media were observed and the total colonies were counted. Selected colonies were isolated for further identification using several biochemical tests, namely catalase test, oxidase test, Sulfide Indole Motility test, Methyl Red-Voges Proskauer test, and the carbohydrate fermentation test. The results of the research succeeded in isolating lactic acid bacteria from the genera Lactobacillus, Leuconostoc, and Weissella. Orangutans produced the highest total lactic acid bacteria, which was 3.1 x 108 CFU/ml.
Keyword: lactic acid bacteria, primates, total plate count

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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