Judul: Analisis Keragaman Genetik Bakteri dalam Teknologi Budidaya Bioflok dengan Teknik ARDRA gen 16S-rRNA
Abstrak: A new approach to reducing farmed waste is aquaculture with biofloc technology (BFT-Bio-flocs technology). Bacteria is the main constituent in aquaculture systems with biofloc. This study aimed to analyze the genetic diversity of bacteria biofloc using 16S-rRNA PCR with ARDRA technique. A total of 38 dominant bacterial isolates was obtained and of these isolates, 16S-rRNA gene was then isolated and amplified using PCR. The 16S-rRNA gene of the isolates was then cut using HaeIII (5’-GG•CC) and HhaI (5’-GCG•C) restriction enzymes resulting an ARDRA pattern which was further used as the binary data for the construction of phylogenetics tree that can be used to estimate the group of bacteria. The result with HaeIII cutting restriction enzyme from bacteria bioflocs obtained 11 ARDRA patterns, while with the restriction enzyme HhaI obtained 8 ARDRA patterns. Phylogenetics of bacterial populations on tree water biofloc cultivation system consisting of at least 13 different bacterial species. Result of sequencing from 2 gene sample 16S-rRNA identified Microbacterium foliurum, and Pseudomonas putida.
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Judul: Keragaman genetik Bacillus sp. Rizobakteri pemacu pertumbuhan tanaman berdasarkan sekuen gen 16S rRNA dan amplified rDNA restriction analysis
Abstrak: Sebelas isolat Bacillus sp. rizobakteri pemacu pertumbuhan tanaman telah berhasil diketahui keragaman genetiknya melalui metode sekuens gen 16s rRNA dan ARDRA. Hasil BlastN menunjukkan bahwa tidak terdapat dominansi spesies Bacillus sp. yang digunakan. Penggunaan empat enzim restriksi yaitu HaeIII, CfrI, dan Hinfl telah berhasil menunjukkan keragaman genetik pada Bacillus sp. Penggunaan enzim restriksi RsaI menunjukkan keseragaman pada semua isolat. Hasil dari ARDRA terdiri atas filotipe yaitu Filotipe I (Bacillus sp. Cr24, Cr33, Cr64, dan Cr68), filotipe I1 (Bacillus ps. '2131 dan Cr66), filotipe 111 (Bacillus sp. Cr44 dan Cr71), dan filotipe IV (Bacillus sp. Cr67, Cr 28, dan Cr69) yang dibuat pohon filogenetiknya dengan metode neighbor-joining menggunakan program Treecon 1.3b. Hasil filogenetik menggunakan sekuens gen 16s rRNA juga menunjukkan kekerabatan antar spesies yang digunakan. ARDRA dapat digunakan untuk melihat keragaman spesies berdasarkan situs pemotongannya.
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Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4