Figure 8

Relationship between environmental factors and Ni/Co utilization traits in bacteria. All organisms were classified into four groups: Ni (+), i.e., containing Ni utilization trait; Ni (-), i.e., lacking Ni utilization trait; Co (+), i.e., containing Co utilization trait; Co (-), i.e., lacking Co utilization trait. (A) Habitat; (B) Different host-associated life styles.