The research was conducted at the Laboratory of Marine Molecular Biology and Pharmacy, Faculty of Fisheries and Marine Sciences, Sam Ratulangi University. This research aims to isolate and analyze the morphology and molecular types of bacteria associated in rotifer’s culture media that use fisheries waste.The research was begin by culturing bacteria in rotifer maintenance media using Nutrient Broth media. After bacterial isolates were obtained, morphological characterization and DNA extraction was carried out. extraction was done using DNeasy Blood and Tissue Kit (Qiagen). After DNA was obtained, DNA was amplified through the Polymerase Reaction Chain (PCR) machine using a 16S RNA primer, followed by the separation of PCR products through electrophoresis and detection through UV Transluminator. The target PCR product was determined by comparing the 100 bp ladder DNA, with a yield of around 1400 bp, which was measured using ladder DNA available in the laboratory. The DNA that was successfully amplified was sent to be sequenced to determine the species of each microbe obtained.Based on the results of the research conducted, obtained Bacillus sp. bacteria associated with rotifer maintenance media.Keywords: Bacteria, Culture Media, DNA Extraction, PCR, Sequencing ABSTRAKPenelitian ini dilakukan di Laboratorium Biologi Molekuler dan Farmasetika Laut, Fakultas Perikanan dan Ilmu Kelautan, Universitas Sam Ratulangi.  Penelitian ini bertujuan untuk mengisolasi dan menganalisis morfologi dan molekuler jenis-jenis bakteri yang berasosiasi dalam media pemeliharaan rotifer yang menggunakan limbah perikanan.Penelitian dilakukan dengan cara mengkultur bakteri yang ada pada media pemeliharaan rotifer menggunakan media Nutrient Broth. Setelah isolat bakteri didapatkan, dilakukan karakterisasi morfologi dan dilakukan ekstraksi DNA.  ekstraksi dilakukan menggunakan DNeasy Blood and Tissue Kit (Qiagen).  Setelah DNA didapatkan, DNA diamplifikasi melalui mesin Polymerase Reaction Chain (PCR) menggunakan primer 16S RNA, diikuti dengan pemisahan produk PCR melalui electrophorisis dan deteksi melalui UV Transluminator. Produk PCR target ditentukan dengan membandingkan ladder DNA 100 bp, dengan hasil sekitar 1400 bp, yang diukur menggunakan ladder DNA yang tersedia di laboratorium.  DNA yang berhasil diamplifikasi, dikirim untuk dilakukan sekuensing untuk mengetahui spesies dari setiap mikroba yang didapatkan.  Berdasarkan hasil penelitian yang dilakukan, diperoleh bakteri Bacillus sp. yang berasosiasi pada media pemeliharaan rotifer. Kata Kunci: Bakteri,  Media Pemeliharaan, Ekstraksi DNA, PCR, Sekuensing

Abstract. Wullur S, Napitupulu H, Wantania LL, Ginting EL, Warouw V, Tallei TE, Rumengan IFM. 2020. Molecular identification of bacteria isolated from culture medium of rotifer fed on fishery waste diet. Biodiversitas 21: 2735-2740. The aim of this study was 16S-rRNA sequences based molecular identification of bacteria isolated from culture medium of rotifer fed with fishery waste diet (FWD). We cultured rotifer Brachionus rotundiformis in sterilized seawater (salinity 25 ppt) using FWD, following the procedure in Patent No. P00201609066. Bacteria from the culture were collected, homogenized, diluted 10 to 1000 fold, spread on agar plates and incubated at 370C for 24 to 48 hours. Representative colonies of the bacteria according to their morphologies were isolated for further characterization. Genomic DNA of the isolates were extracted, and the 16S rRNA gene of the isolates were amplified. Polymerase Chain Reaction (PCR) product of each isolate was sequenced and queried against the NCBI GenBank database. Six different isolates based on size, color, elevation, margin, and colony were observed during 24-48 hours incubation at 370C. The 16S rRNA genes of the six isolates were successfully amplified and produced DNA band at 1300-1500 bp, with quality value equal to or greater than 20 (QV20+) of each entire sequence around 941-1253 bases. Basic Local Alignment Search Tool (BLAST) queries in the NCBI GenBank and EzBioCloud database using the 16S-rRNA gene sequences showed that the six isolates belong to four different genera, i.e: Bacillus, Staphylococcus, Vibrio, and Alteromonas.

Abstract. Wullur S, Napitupulu H, Wantania LL, Ginting EL, Mamangkey NGF, Smolak R, Ogello E. 2020. Molecular identification of bacteria isolated from culture medium of the gold-lipped pearl oyster Pinctada maxima larvae. Biodiversitas 21: 5291-5297.  This study was conducted for the molecular identification of bacteria species isolated from culture medium of the gold-lipped pearl oyster, Pinctada maxima larvae. The pearl oysters were cultured using live-microalgae (Isochrysis sp) and fish waste diet (FWD) as food sources.  Bacteria were isolated from the oyster larvae and identified based on the 16S rRNA gene sequence. The isolated bacteria were grown on agar plates and incubated at 37°C for 24 to 48 hours. Representative colonies of the bacteria were selected and cultured for molecular analysis.  The 16S rRNA genes of the bacteria were amplified and the sequences were matched with the NCBI GenBank database. Seven different colonies were observed based on morphological characters. Similarity test by conducting the Basic Local Alignment Search Tool (BLAST) in the NCBI GenBank database, using the 16S rRNA gene sequences showed that the seven isolates colonies possess high similarity to five bacteria species i.e. Pseudomonas pachastrellae, Vibrio alginolyticus, Bacillus filamentosus, Bacillus cereus and Idiomarina fontislapidosi belonging to four different genera i.e. Bacillus, Staphylococcus, Vibrio, and Alteromonas.