Widiyanti, Setyo Erna
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Studi Kinetika Konsumsi Glukosa oleh Aspergillus Niger dalam Produksi Bioethanol dari Lignoselulosa Widiyanti, Setyo Erna
INTEK: Jurnal Penelitian Vol 4 No 1 (2017): April 2017
Publisher : Politeknik Negeri Ujung Pandang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (921.5 KB) | DOI: 10.31963/intek.v4i1.98

Abstract

Global warming resulted from CO2 level increase in the atmosphere has caused elevation of earth temperature and uncertain climate changes. To prevent the rise of CO2 in the atmosphere can be done by using biomass fuel such as bioethanol. The raw materials of bioethanol can be derived from oil palm empty fruit bunch. Enzymatic hydrolysis utilizes cellulase-producing fungus and in this research, Aspergillus niger was chosen. The glucose produced is consumed by A niger as carbon source and this is undesirable, therefore it should be minimized as low as possible. Knowing the rate of glucose consumption is important to have a model of the hydrolysis reaction rate which will be helpful in the design process on an industrial scale hydrolysis reactor. This study aimed to determine the equations that can be used to approximate the growth rate of A. niger, glucose consumption, the formation of citric acid, and the kinetic parameters used to modeling the kinetics of glucose consumption by A. niger. Kinetics of glucose consumption by A. niger was studied in batch system with variation of initial glucose concentration of 30, 50, 70 g/l. The growth rate of A. niger, glucose consumption, and the formation of citric acid were modeled using 3 equations; i.e. Monod with non-competitive product inhibition, Luedeking-Piret, and Luedeking-Piret growth associated product formation, respectively. The values of kinetic parameters such as μmax, Ks, Kp, were 0.65 hour-1, 157.5 g/l, 0.3 g/l, for initial glucose concentration of 30, 50, 70 g/l, respectively. The values of α (kinetic parameter for growth associated product formation and α would be equal to Yp/x) and Yx/s were 0.4903, 0.8531, 0.9863; 0.5124, 0.2704, 0.2381, for initial glucose concentration of 30, 50, 70 g/l, respectively. Higher initial glucose concentration would increase α but it lowered Yx/s.
Pengaruh Waktu terhadap Kestabilan Nanopartikel Emas yang Disintesis Menggunakan Ekstrak Air Daun Jati (Tectona Grandis) Termodifikasi Mercaptopropionic Acid (MPA) Yasser, M; Widiyanti, Setyo Erna
INTEK: Jurnal Penelitian Vol 6 No 1 (2019): April 2019
Publisher : Politeknik Negeri Ujung Pandang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (50.592 KB) | DOI: 10.31963/intek.v6i1.1123

Abstract

Gold nanoparticles were synthesized using teak leaf water extract modified with Mercaptopropionic Acid (MPA). The observations for 6 days using UV-Vis spectroscopy, obtained stable gold nanoparticles which were characterized by the maximum wavelength absorption produced in the range of 538.5 nm - 541 nm.