Fig. 1.

(a) Growth curve of a culture of strain EN76^T grown at 42 °C with 2 mM NH₄Cl and 1 mM pyruvate. Cell counts, ammonium consumption and nitrite production were used to follow growth. Data represent mean values of triplicate cultures with standard deviations plotted (sometimes smaller than symbols). (b) Acceleration of growth of strain EN76^T since purification of the strain in 2010 (Tourna et al., 2011). The cultivation conditions were as follows: July 2010 and November 2010, 37 °C, 1 mM NH₄Cl, 1 mM pyruvate; March 2013, 37 °C, 1 mM NH₄Cl, 0.1 mM pyruvate; July 2013, 42 °C, 1 mM NH₄Cl, 0.8 mM pyruvate; November 2013, 42 °C, 2 mM NH₄Cl, 1 mM pyruvate. Nitrite production was used to follow growth. Data represent mean values of replicated cultures (three to five replicates) with standard deviations plotted (sometimes smaller than symbols). Data points previously published in Fig. 3(b) of Tourna et al. (2011) (i.e. July 2010) were included in the figure.