Growth of the mxaF mutant strain in MP methanol medium containing 20 μM Ca (◆) and 20 μM Ca with increasing concentrations of La: 2.5 nM (■), 5 nM (▲), 10 nM (×), 25 nM (+), 50 nM (●), 100 nM (-), 250 nM (○), 500 nM (×), 1 μM (♢), 2 μM (□), and 20 μM (△). The growth curve shows representative data from three biological replicates. Variation in growth rates between biological triplicates was within 1%.