Browsing by Author "Lestari, Diana"

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    Produksi Enzim Protease Alkalin Dari Bacillus substilis Dengan Media Limbah Cair Tahu
    (2016-02-25) Evelyn; Chairul; Lestari, Diana; Purnama, Fauziah R
    Proteases are one of the most important industrial enzymes accounting for nearly 60% of the total worldwide enzyme sales. Of these, alkaline proteases are employed primarily as cleansing additives to detergents and in bating of hides and skins in leather industries. Among the various proteases, bacterial proteases are the most significant, compared with animal and fungal proteases, especially from Bacillus species. This research try to produce enzyme of protease alkaline by using submerged fermentation technology and exploit local soybean cake liquid waste medium to determining optimum medium composition, temperature and pH in producing the enzyme constructively Bacillus substilis. In order to get the optimum concentration fermentation media and pH, research was conducted of flour concentration at 10%, 20%, 30%, and pH at 7, 8, 9, 10 and 11 respectively. The optimum fermentation temperature of alkaline protease was obtained with temperature variation at 30, 40, 50, 60 and 70 oC. Fermentation process took place during 72 hour to the each variable and conducted by intake of sample every 12 hours. Enzyme activities were determined by using Protease Colorimetric Detection Kits from Sigma, which were calculated by rate of tyrosine existing in mixture of reagent and samples were analyzed using spectrophotometer. Result showed that the optimum conditions obtained were at fermentation medium (grist flour) concentration of 10%, early pH media of 9 and temperature of incubation of 30 oC with maximum enzyme activity 32,90 unit/ml.
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    STUDI AWAL PENGAKTIFAN KARBON SEBAGAI BAHAN PENYERAP MENGGUNAKAN PENGAKTIFAN KIMIA DAN IRADIASI GELOMBANG MIKRO
    (2016-02-01) Lestari, Diana; Farma, Rakhmawati; Awitdrus
    A microwave induced potassium hydroxide activation was used to produce Paraserianthes falcataria wood based activation carbon. The activation process was carried out at irradiation times 10 minutes with various of power irradiation of 540, 630, 720 and 810 Watt. The physical propertie of activated carbon was characterized by X-ray diffraction, scanning electron microscopy and energy dispersive of X-rays, and nitrogen adsorption isotherm the power of microwave irradiation at 720 Watt resulted the highest of methylene blue absorption of 15.9234 mg/g. Analysis of microstructures of activated carbon showed that the stack high (Lc) is inverse proportional with stack diameter (La). The stack high correspondent to the surface area of activated carbon. The higher of surface area of activated carbon resulted from the microwave irradiation power of 720 Watt.