Scientists studied the types of bacteria in Arctic Ocean sediment using different methods. They found 11 different bacterial strains using traditional techniques, which belonged to three main groups: γ-proteobacteria, Bacteroidetes, and Actinobacteria. These bacteria were able to grow in cold temperatures without salt and had enzymes that break down substances. By analyzing DNA, they discovered 67 different types of bacteria, with most belonging to γ-proteobacteria. Other groups included δ- and e-proteobacteria, Bacteroidetes, α-proteobacteria, Actinobacteria, Fusobacteria, Nitrospirae, and an unknown group.