Figure 7.

Growth of dissimilatory arsenate (A), sulphate (B), and iron (Fe III) (C) reducers under anaerobic conditions on minimal salt medium supplemented with 5 mM sodium lactate and 2.5 mM of proper salt of electron acceptor (${\text{AsO}}_4^{3-}$, ${\text{SO}}_4^{2-}$, or Fe³⁺). Growth rates (number of doublings that occur per hour) are shown in the square.