#TITLE_ALTERNATIVE#

• Main Author: MARLIANA SRIKATON (10503022), DIAN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/7622
• Institution: Institut Teknologi Bandung

The α-amylase (GH 13) family is the enzyme family that hydrolyze the α-1,4-glycoside linkage on starch to produce oligosaccharides, dextrin, and glucose. The aim of this research is to characterize activity of α-amylase, secreted from gastrointestinal tract of the earthworm P. excavatus, including effect of temperature and pH on its activity, as well as microbial identification producing the enzyme. The α-amylase assay was performed by the method of Fuwa. The enzyme activity remained unchanged up to 70oC, and overheating of the protein losing its activity, as the structural damage. The α-amylase was relatively stable in wide range of pH value between 3 and 12, except pH value between 4 and 5 likely owing to its isoelectric point. The fluorescence spectra of the proteins in a various pH value showed that protein structure was relatively stable between pH 3 and 9, and they underwent a hydrophobic core unfolding at pH value above 10. Microbial analysis of fresh homogenate isolated from gastrointestinal tract of the earthworm found that symbion bacteria produced α-amylase that is similar to homogenate extract. This suggested that the symbion bacteria mediated starch degradation in gastrointestinal tract of earthworm.