Judul: Analysis of the Effect of Bacillus sp. Probiotic Application for Controlling Vibrio spp. Bacterial Population in Vannamei Shrimp (Litopenaeus vannamei) Cultivation.
Abstrak: Bakteri Vibrio spp. merupakan salah satu jenis bakteri patogen yang sering ditemukan di lingkungan perairan, seperti pada budidaya udang. Infeksi Vibrio spp. mampu menyebabkan beberapa penyakit pada udang seperti vibriosis, Acute Hepatopancreatic Necrosis Disease (AHPND), dan feses putih. Pengendalian jumlah populasi dan infeksi oleh Vibrio spp. dalam budidaya udang dengan penggunaan probiotik Bacillus sp. pada pakan udang. Bakteri Bacillus sp. memiliki kemampuan anti quorum sensing dengan mengganggu acyl homoserine lactones (AHL), sehingga AHL Vibrio spp. tidak mencapai kondisi kuorum. Penelitian ini bertujuan menganalisis pengaruh aplikasi probiotik Bacillus sp. untuk pengendalian populasi bakteri Vibrio spp. pada budidaya udang vaname. Penelitian dilakukan hingga Day of Culture (DOC) 120 pada 6 kolam tambak terletak di PT. Sentra Budidaya Biotek, Kabupaten Sumbawa Barat, Nusa Tenggara Barat. Metode yang digunakan terdiri dari persiapan tambak, aklimatisasi benur, perbanyakan dan aplikasi probiotik Bacillus sp., Pemeriksaan kualitas air, isolasi dan perhitungan bakteri Vibrio spp., uji histopatologi hepatopankreas udang, sampling udang, dan panen udang. Aplikasi probiotik Bacillus sp. memberikan dampak positif terhadap pengendalian populasi bakteri Vibrio spp., kualitas air tambak, uji histopatologi hepatopankreas udang, dan hasil panen udang. Hal ini ditunjukkan dengan populasi Vibrio spp. dibawah ambang batas, terkendalinya kualitas air, terkendalinya infeksi dari Vibrio spp. pada hepatopankreas udang dan jumlah produksi udang mencapai target., Vibrio spp. are a type of pathogenic bacteria commonly found in aquatic environments, such as in shrimp pond. Infections by Vibrio spp. can lead to several shrimp diseases such as vibriosis, Acute Hepatopancreatic Necrosis Disease (AHPND), and white feces syndrome. Controlling the population and infections of Vibrio spp. in shrimp pond can be achieved through the use of Bacillus sp. in shrimp feed. Bacillus sp. have anti-quorum sensing abilities by disrupting acyl homoserine lactones (AHL), preventing Vibrio spp. from reaching quorum conditions. This study aims to analyze the effects of Bacillus sp. controlling the population of Vibrio spp. in vannamei shrimp pond. The research was conducted until Day of Culture (DOC) 120 in 6 ponds located at PT. Sentra Budidaya Biotek, West Sumbawa, West Nusa Tenggara. The methods included pond preparation, shrimp acclimatization, Bacillus sp. culture and application, water quality assessment, isolation and quantification of Vibrio spp., histopathological examination of hepatopancreas, shrimp sampling, and harvest. The application of Bacillus sp. showed positive impacts in suppressing Vibrio spp. populations, maintaining pond water quality, reducing Vibrio spp. infections in shrimp hepatopancreas, and shrimp production. This was evidenced by Vibrio spp. populations staying below threshold limits, controlled water quality, controlled infections from Vibrio spp. in shrimp hepatopancreas, and achieving the targeted shrimp production.
Keyword: Aplikasi, Litopenaeus vannamei, anti-quorum sensing, Bacillus  sp., Vibrio spp.

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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