CD Skripsi
Deteksi L-Lysine Menggunakan Biosensor Berbasis Sel Ragi Saccharomyces Cerevisiae
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ABSTRACT
Nutritional problems have become a serious problem in the world, including in Indonesia, where stunting is a form of malnutrition in children under five. L-lysine is reported as the main amino acid that must be consumed to prevent stunting in children. The amino acid L-lysine is often used as a food supplement and medicinal product. Therefore, it must be consumed at the right dosage. However, we need a method to monitor and minimize the risks that will arise due to misuse of these doses. In this study, the yeast cells Saccharomyces cerevisiae were used as bioreceptors using a Clark-type oxygen sensor based on Pt-Ag electrodes with the principle of amperometric biosensors. The results of yeast cell metabolic activity were observed by adding L-lysine analyte samples, which were expressed as dissolved oxygen (DO) levels. In this study, the amino acid L-lysine at various concentrations of 100 mM, 200 mM and 300 mM, as well as appetite-enhancing supplements on the market, were used as samples. The DO levels produced in the addition of L-lysine samples for concentrations of 100 mM, 200 mM, and 300 mM were 26.02 %, 20.03 % and 13.47 %, while in the appetite-enhancing supplement samples, the DO levels produced were 15.71 %. The measurement results show that the sensor electrodes can detect DO changes that occur due to the addition of L-lysine samples of each concentration, which affect the metabolic activity of the interaction of yeast bioreceptors and L-lysine analytes. The results of measuring L-lysine concentrations were classified using Principal Component Analysis (PCA) and showed significant differences. The L-lysine concentration value on the score plot graph is determined by the main components of PC1 and PC2. PC1 gives a variance of 59.6 %, while PC2 gives a variance of 25.2 %. The total variance shown for PC1 and PC2 is 84.8 %, meaning that the concentration of L-lysine can be classified properly using the PCA method.
Keywords: L-lysine, Saccharomyces cerevisiae, amperometric biosensor, dissolved oxygen, PCA
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