Energy metabolism of Heliobacterium modesticaldum during phototrophic and chemotrophic growth

BMC Microbiology

Table 4 Enzyme activity of enzymes and relative expression level of genes for acetate metabolism in pyruvate-grown cultures during phototrophic and chemotrophic growth.

	Specific activity (nmole/min/mg protein)
Enzyme activity tested	Phototrophic growth	Chemotrophic growth	Relative gene expression level (light/dark)
acetyl-CoA synthetase (ACS)^a	100 ± 20	N/A	45
acetate kinase (ACK)^a	800 ± 40	600 ± 100	3
phosphotransacetylase (PTA)^a	400 ± 50	500 ± 100	--

^aActivity of ACS was determined by a colorimetric assay of PP_i [39], and activity of ACK and PTA was determined by coupling assays reported previously [18].

ISSN: 1471-2180