Fig. 2.

Enzyme activity of C. thermocellum strains for reactions related to PP_i-linked reactions. These reactions include phosphofructokinase (PFK, EC 2.7.1.11 or 2.7.1.90), pyruvate phosphate dikinase (PPDK, EC 2.7.9.1), pyruvate kinase (PYK, EC 2.7.1.40) and thermostable soluble PPase (EC 3.6.1.1). In the PFK reaction panel, red bars and blue bars represent activity with either ATP or PP_i as the cofactor. In the table at the bottom of the figure, the ‘+’ and ‘−’ signs indicate the presence or absence of heterologous genes at a given locus. The ‘WT’ and ‘Δ’ signs indicate the presence or absence (i.e., by deletion) of native genes. All the reactions were carried out using cell extracts. Missing bars indicate the absence of activity (i.e., below the limit of detection, <0.02 μmol/min/mg). Error bars represent 1 standard deviation (n ≥ 3 biological replicates). Raw enzyme assay data is available as Additional File 1