Characteristics of growth with oxalate
Growth in basal mineral medium with oxalate as sole
carbon source is relatively fast (Fig. 3), μmax values of
about 0.6 were recorded at 25 °C (μmax = 0.15 in Ralstonia
oxalatica, [9]). The growth yield with oxalate in
batch cultures (YM = 4.8 g/mol) was also relatively high as
compared with the yield of R. oxalatica (YM = 3.8 g/mol,
[9]). The upper concentration limit of potassium oxalate
in batch cultures not corrected for pH was 12 g l–1. This
limit was probably determined by the pH increase.
Oxalate is metabolized via the glycolate pathway, as
shown by the presence of glyoxylate carboxylase and the
absence of the key enzymes of the serine pathway, hydroxypyruvate
reductase and L-serine-glyoxylate-aminotransferase
(Table 1).