Isolation and Characterization of Amylase Enzyme Produced by Indigenous Bacteria from Sugar Factory Waste

Abstract

Background Enzymes are biocatalysts commonly used in industries. One of these enzymes is amylase. In Indonesia, most of the enzymes are still imported from overseas. To reduce the production cost, local amylase is needed which can be produced from indigenous microorganisms. Aims This research aims to explore isolates amylase-producing bacteria from a liquid waste of sugar factories, optimize amylase enzyme production, and identify genotypically the indigenous bacterial. Objective This research aims to explore isolates amylase-producing bacteria from a liquid waste of sugar factories, optimize amylase enzyme production, and identify genotypically the indigenous bacterial. Methods This study consists of seven stages: sample preparation, isolation of amylase-producing bacteria, crude amylase extract production, amylase activity assay, optimization of amylase enzyme production, determining the specific activity, and bacterial identification through genotyping. Results This research successfully identified 3 bacterial isolates (G-7, G-8, and G-12) that positively produce amylase enzymes from sugar factory waste. The optimal conditions for amylase enzyme production for all three isolates were at 37°C, pH 7.0, and during the exponential growth phase - at 24 hours for isolate G-8 with specific amylase enzyme activity of 0.198 U/mg, and at 48 hours for isolates G-7 and G-12 with specific amylase enzyme activities of 0.108 U/mg and 0.208 U/mg respectively. The 16S rRNA gene identification results showed that G-7, G-8, and G-12 belong to the species Bacillus infantis, Bacillus flexus, and Pseudomonas nitroreducens respectively. Conclusion The species Bacillus infantis, Bacillus flexus, and Pseudomonas nitroreducens has shown great potential for the production of amylase enzyme.