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

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