Judul: Karakterisasi Xilanase Dari Bakteri Xilanolitik Asal Tanah Hutan Taman Nasional Bukit Duabelas Jambi Indonesia
Abstrak: Xilanase merupakan enzim ekstraseluler yang dapat dihasilkan oleh mikroba dan memiliki kemampuan mendegradasi xilan menjadi xilo-oligosakarida (XOS) dan xilosa. Xilanase banyak digunakan dalam bidang industri kertas dan produksi bioetanol. Aplikasi xilanase yang masih belum optimal salah satunya disebabkan oleh kurang tersedianya biakan mikroba unggul penghasil xilanase. Tujuan penelitian ini adalah mengetahui karakteristik xilanase dari isolat bakteri xilanolitik asal tanah Hutan Taman Nasional Bukit Duabelas Jambi, Indonesia. Isolat bakteri XJ20 merupakan isolat terpilih yang akan diuji lebih lanjut aktivitas dan karakteristik enzimnya. Aktivitas xilanase diukur dengan menggunakan metode 3.5-dinitrosalicylic acid (DNS). Xilanase yang dihasilkan oleh isolat XJ20 memiliki tiga puncak tertinggi aktivitas enzim yaitu pada jam ke-6 (0.015 U/mL), jam ke-14 (0.012 U/mL) dan jam ke-20 (0.007 U/mL). Puncak pertama dan puncak kedua mencapai aktivitas tertinggi pada suhu 70 oC namun puncak pertama optimum pada pH 4.0 dan puncak kedua pada pH 7.0. Pada pH 4.0 xilanase yang diinkubasi pada suhu ruang dan suhu 70 ˚C memiliki waktu paruh berturut-turut 9 jam dan 6 jam, sedangkan pada pH 7.0 4 jam dan 3 jam. Stabilitas enzim lebih baik pada pH 4.0 dan pada suhu ruang.
Keyword: aktivitas enzim, DNS, stabilitas enzim, xilanase, xilanolitik

Judul: Isolasi dan Pencirian Xilanase dari Bakteri Asal Tanah Hutan Taman Nasional Bukit Duabelas, Jambi, Indonesia
Abstrak: Xylanase is a xylan-degrading enzymes which are useful to improving the bioconversion of lignocellulosic biomass into useful products. Broad application of xylanase have not optimized due to the lack of superior microbes. The aim of this study is to isolate bacterial origin Bukit Duabelas National Park, Jambi and characterize its xylanase, including its pH optimum, temperature optimum, and stability. A total of 28 potential isolates have been isolated from Bukit Duabelas National Park soil, Jambi and three were successfully characterized its xilanase (isolates 10, 18, and 27). Isolate 10 reached the highest producing extracellular xylanase at 12th and 36th hours of culture incubation with optimum activity at pH 6, temperature 40 °C and 90 oC. Isolate 27 reached its highest producing extracellular xylanase at 12th and 30th hours of culture incubation. The optimum condition of xylanase isolate 27 occurred at pH 5, temperature 90 oC and 50 oC, while xylanase isolate 18 achieve its optimum production time at the 18th and 36th hours of incubation culture. Xylanase isolate 18 achieved its optimum condition at pH 5 and temperature 90 oC and has half-life time 1 hour 7 minutes.
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Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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