Judul: Optimasi Kondisi Produksi Enzim Amilase dari Bakteri Laut Bacillus sp.
Abstrak: enzyme amylase. Microbial community is the largest marine biomass that enables many new sources producing enzyme. This study aimed to determine the optimum state of environmental conditions and nutrient media production of marine bacterium Bacillus sp. Various parameters such as substrate concentration, pH production, fermentation temperature, co-substrate, and nitrogen sources have been determined the optimal conditions. The method used is the spectrophotometric method. The maximum production of amylase enzyme obtained at a concentration of 1% starch substrate, pH 7, 30°C, maltose as co-substrate production, and casein as a nitrogen source with a value most optimum amylase enzyme activity, respectively for 2.547 U/mL, 2.109 U/mL, 2.414 U/mL, 2.675 U/mL, and the last 2.335 U/mL.
Keyword: Bogor Agricultural University (IPB), temperature., substrate, pH, optimization, nitrogen source, co-substrate, Bacillus sp., amylase activity

Judul: Optimasi Kondisi Produksi Enzim α-Amilase dari Bacillus licheniformis dengan Metode Fermentasi Padat pada Substrat Limbah Dedak Padi.
Abstrak: Enzim amilase merupakan kelompok enzim yang sangat dibutuhkan dalam bidang industri dan produksi komersialnya dari mikroorganisme mencapai 25%- 33% dari pasaran enzim di dunia. Tujuan penelitian ini mendapatkan kondisi optimum produksi α-amilase berdasarkan aktivitas ekstrak kasar enzim amilase dari bakteri Bacillus licheniformis dengan metode fermentasi substrat padat menggunakan limbah pertanian dedak padi. Optimasi dilakukan dengan berbagai parameter seperti waktu produksi (fermentasi), konsentrasi substrat, pH produksi, suhu fermentasi, dan ko-substrat. Pengukuran aktivitas amilase menggunakan metode DNS dan diukur absorbansinya menggunakan spektrofotometri pada panjang gelombang 540 nm. Produksi enzim α-amilase maksimum didapatkan pada waktu fermentasi selama 36 jam, dengan penambahan substrat dedak padi pada konsentrasi 50 g/L, pada kondisi pH 8, suhu 370C, maltosa sebagai kosubstrat dengan konsentrasi 1.5%.
Keyword: Amylase activity, Bacillus licheniformis, Optimization

Judul: Posisi Filogenetik Kura-Kura Carettochelys Insculpta  (Reptillia: Testudinata)
Abstrak: Carettochelys insculpta is an endemic freshwater turtle of southern Papua and northern Australia. Phylogenetic position of this turtle is remain unresolved until now. Most of the research conducted show close relationships of C. insculpta and members of Trionychidae family. However, some of the research show distance between C. insculpta and members of Trionychidae family. This research is conducted to analyze phylogenetic relationship between C. insculpta and other members of Testudinata using 12S rRNA, 16S rRNA, and both gene as markers. DNA samples were obtained from three different organisms of C. insculpta. Two species used as outgroups were Alligator mississippiensis and Iguana iguana. Phylogenetic analysis was carried out using Neighbor-Joining method with Felsenstein 1981 (F81) modeltest. A polytomy tree of Testudinata was produced by using 12S rRNA gene. However, analysis using 16S rRNA and both genes as markers confirmed that C. insculpta was located between the Chelonidae and the Trionychidae family.
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