Judul: : Seleksi Bakteri Kandidat Probiotik Potensial Asal Air Laut dan  Sedimen Tambak Udang sebagai Penghambat Vibrio  parahaemolyticus
Abstrak: Vibrio parahaemolyticus merupakan salah satu bakteri patogen penyebab penyakit vibriosis. V. parahaemolyticus strain tertentu yang mengekspresikan toksin PirA dan PirB merupakan penyebab utama penyakit Acute Hepatopancreatic Necrosis Disease pada udang. Upaya pencegahan infeksi bakteri pada udang yaitu melalui aplikasi probiotik dengan diawali proses seleksi kandidat probotik potensial. Penelitian ini bertujuan mendapatkan isolat dan melakukan karakterisasi bakteri probiotik potensial yang berasal dari air laut dan sedimen tambak sebagai upaya penghambat V. parahaemolyticus. Penelitian dilakukan secara eksperimental menggunakan Rancangan Acak Lengkap (RAL) dengan 3 perlakuan dan 2 ulangan pada uji antagonistik in vitro (kultur bersama) dan uji non patogenisitas. Hasil penelitian berhasil mendapatkan 37 isolat kandidat probiotik dengan 10 isolat memiliki aktivitas enzim terbesar. Uji antagonistik in vitro dengan metode Kirby-Bauer dan uji kultur bersama didapatkan 2 isolat terbaik dengan kode LAZ-2 dan SAZ-22. LAZ-2 dan SAZ 22 merupakan bakteri kandidat probiotik terpilih yang memiliki aktivitas enzimatik, mampu menghambat pertumbuhan bakteri patogen V. parahaemolyticus serta tidak bersifat patogen terhadap udang vaname., Vibrio parahaemolyticus is one of the pathogenic bacteria that cause vibriosis. V. parahaemolyticus strain that express the PirA and PirB toxin is the main causative agent of Acute Hepatopancreatic Necrosis Disease in shrimp. The effort to prevent bacterial infections in shrimp is through the application of probiotics, which begins with the process of screening for potential probiotic candidates. This study aims to obtain isolates and characterize the potential probiotic bacteria isolated from seawater and pond sediments as an inhibition effort V. parahaemolyticus. The study was carried out experimentally using a completely randomized design (CRD) with 3 treatments and 2 replications in an antagonistic test (co culture) and in the non-pathogenicity test. The results of the study succeeded in obtaining 37 probiotic candidate isolates with 10 isolates having the greatest enzyme activity. Antagonistic test in vitro with the Kirby Bauer method and co-culture, the 2 best isolates with the LAZ-2 and SAZ-22 codes. LAZ-2 and SAZ-22 are selected probiotic candidates have enzymatic activity, capable of inhibiting the growth of V. parahaemolyticus and are not pathogenic to vannamei shrimp.
Keyword: probiotic, vannamei shrimp, Vibrio parahaemolyticus

Judul: Aplikasi Probiotik Lactobacillus plantarum dan Bacillus cereus untuk Pencegahan Vibriosis pada Udang Vaname Litopenaeus vannamei
Abstrak: Penggunaan antibiotik untuk pengendalian vibriosis pada udang vaname menimbulkan beberapa permasalahan seperti resistansi bakteri patogen serta residu antibiotik pada produk akuakultur dan lingkungan perairan. Probiotik diharapkan dapat menjadi alternatif lain yang ramah lingkungan. Penelitian ini bertujuan untuk menguji pengaruh pemberian probiotik L. plantarum dan B. cereus serta gabungan keduanya terhadap respons imun dan resistansi udang vaname yang diinfeksi V. parahaemolyticus. Udang vaname yang digunakan memiliki bobot awal 0.55+0.01 g, dipelihara selama 40 hari dengan perlakuan probiotik kemudian diuji tantang dengan V. parahaemolyticus dan diamati respons imun dan resistansinya selama tujuh hari. Perlakuan yang diberikan meliputi kontrol positif (K+), kontrol negatif (K-), probiotik L. plantarum (Lp), probiotik B. cereus (Bc), dan gabungan probiotik (Lp+Bc). Hasil penelitian menunjukkan bahwa kinerja pertumbuhan, respons imun dan resistansi udang vaname yang diberikan probiotik lebih baik dibandingkan kontrol. Respons imun terbaik pada sebelum maupun setelah uji tantang dengan V. parahaemolyticus terdapat pada perlakuan Lp+Bc. Pemberian probiotik L. plantarum dan B. cereus serta gabungan keduanya mampu meningkatkan kinerja pertumbuhan, respons imun dan resistansi udang vaname terhadap infeksi V. parahaemolyticus, dengan nilai respons imun terbaik pada perlakuan gabungan kedua probiotik., The use of antibiotics to control vibriosis in white shrimp raises several problems such as resistance to pathogenic bacteria and antibiotic residues in aquaculture products and the aquatic environment. Probiotics are expected to be another environmentally friendly alternative. This study aimed to examine the effect of giving probiotics L. plantarum and B. cereus and their combination on the immune response and resistance of white shrimp infected with V. parahaemolyticus. The white shrimp used had an initial weight of 0.55+0.01 g, reared for 40 days with probiotic treatment and then challenged with V. parahaemolyticus and observed immune response and resistance for seven days. The treatments included positive control (K+), negative control (K-), L. plantarum probiotic (Lp), B. cereus probiotic (Bc), and a combination of probiotics (Lp+Bc). The results showed that the performance growth, immune responses, and resistance of white shrimp given probiotics was better than the control. The best immune response before and after the challenge test with V. parahaemolyticus was found in Lp+Bc treatment. The administration of probiotics L. plantarum and B. cereus and their combination was able to increase growth performance, immune response, and resistance of white shrimp against V. parahaemolyticus, with the best immune response value in combined treatment of two probiotics.
Keyword: Bacillus cereus, Lactobacillus plantarum, Probiotik, Udang vaname, Vibrio parahaemolyticus

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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