Lake Tanganyika is the second largest and deepest lake on Earth, with a maximum depth around 1400m. It is famous in the field of ecology for its rich animal biodiversity, yet little is known about the microbes of the lake. Lake Tanganyika’s water column is extremely unique, it is permanently separated (stratified) into two distinct layers, a layer of oxygenated water floating atop a layer of anoxic (no oxygen) waters. In fact, everything below ~ 100m is devoid of oxygen, making Lake Tanganyika the largest body of anoxic freshwater on Earth (besides groundwater). Yet, many bacteria and archaea are able to live in anoxic conditions, due to their diverse metabolism. Working with collaborators in the US, Germany and Tanzania, we are seeking to study the microbial ecology and functions of the microbes living in this unique lake.