Isolation and Characterization of Bacteria from River Origin in Mandailing Natal North Sumatera

Abstract The indicator of water pollution according to microbiological standards is the presence of microbiological pollutants. To see the presence of bacteria in the waters, it is necessary to study the isolation and characterization of these bacteria. The existence of the river in the Mandailing Natal area has experienced a change in character due to gold mining activities along the river flow. The purpose of this study was to determine the types of bacteria in the river in the Mandailing Natal area of North Sumatra. This research was conducted at the Laboratory of Microbiology, Department of Biology, Faculty of Mathematics and Natural Sciences, State University of Medan. The research period was from June to October 2020. The population in this study was the water of the Batang Gadis Mandailing Natal river, North Sumatra. The sample in this study is the Batang Gadis river water around the Mandailing Natal gold mine, North Sumatra. The research was carried out by taking samples and isolating bacteria which included planting the samples on media enriching the planting of the samples on various growing media, purifying bacterial colonies and observing the morphology of bacterial colonies. The results showed that there were 6 bacterial isolates living in river waters in Mandailing Natal, North Sumatra.