Judul: Purification and Characterization of Extracellular Mananase Streptomyces purpurascens
Abstrak: Manan is the major component of plant hemicellulose is the second most abundant polysaccharide in nature. As a renewable subtance, there is abundance of hemicellulose in nature that can be degraded as useful end product. Mananase is a group of enzyme that has ability to hydrolyse hemicellulose into manan or polymer of manosa and manooligosaccharides. Streptomyces purpurascens produce extracelluler mananase that has unique characteristic; optimum temperature and pH is 50°C and 6.5 respectively. The purpose of this research was to purify and characterize the mananase Streptomyces purpurascens. Crude extract of mananase was precipitated with 70% acetone gradually, purified with ion exchange chromatography (DEAE cellulosa) and continue with gel filtration chromatography (Sephadex G-IOO). The molecular mass of the purified mananase after ion-exchange and gel filtration was estimated 95.072 kDa and 81.606 kDa. The optimum temperature and pH was 50°C and 6.5 respectively.
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Judul: Purifikasi Parsial dan Karakterisasi Enzim Mananase dari Bacillus pumilus
Abstrak: Bacillus pumilus isolate is one of bacterial collection from Biotechnology Culture Collection (BTCC) LIPI, isolated from Pari island waters was examined to determine the ability of bacteria to degrade mannan from Locust Bean Gum (LBG). Based on qualitative analysis, this isolate showed the abilities to degrade mannan while the quantitative analysis showed the highest mannanase activity was obtained on the third day of incubation time at 3,2 U/mL with 0,9 U/mg specific activity. Initial purification using ultrafiltration 5000 WMCO showed mannanase activity at 5,1 U/mL with 1,44 U/mg specific activity. Enzyme purification by gel filtration produced a peak in fraction no.31 with mannanase activity at 4,2 U/mL with 4,00 U/mg specific activity. Analysis of hydrolitic products by thin layer chromatography showed that the main products from Locust Bean Gum are manobiose, manotetraose and manohexaose. Maximum activity of the mannanase enzyme produced by B. pumilus isolate occurred at pH 5,0 and temperature of 40°C. This enzyme has 30,17 kDa single protein band when running with SDS PAGE with Michaelis Menten (Km) and maximum velocity (Vmax) at 0,076 mg/mL and 0,02 U/mg respectively.
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Judul: Efek Tempo pada Angka Kelahiran Total dan Angka Harapan Hidup
Abstrak: Kelahiran dan kematian meupakan komponen utama dalam demografi yang digunakan untuk membuat kebijakan sosial dan kesehatan. Angka kelahiran total dan angka harapan hidup biasanya digunakan sebagai indikator kelahiran dan kematian. Indikator tersebut sering dihitung menggunakan ukuran periode daripada kohort karena ukuran periode membutuhkan data yang lebih mudah dan dapat menggambarkan kejadian sekarang. Pada karya tulis ini dibahas adanya efek tempo pada kelahiran dan kematian yang mempengaruhi angka kelahiran total dan angka harapan hidup periode. Efek tempo ini disebabkan oleh adanya perubahan rata-rata umur wanita saat melahirkan atau perubahan rata-rata umur seseorang meninggal. Pada kasus kelahiran juga terdapat efek kuantum akibat perubahan jumlah kelahiran yang terjadi pada suatu periode, sedangkan pada kematian tidak ada efek kuantum karena kematian bukan kejadian yang berulang.
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