Light plays an important role in the transcriptional regulation of photosynthetic apparatus. The influence of oxygen and light conditions on the protein expression of Rhodobacter sphaeroides was investigated using a proteomic approach. The R. sphaeroides was grown aerobically under dark cultivation (D24) and light cultivation (L24) for 24 h. An average of 950 distinguishable spots were obtained on 2-D analytic gel for D24 and L24 conditions, of which 48 proteins exhibited significant changes in protein expression levels. Among the 48, 31 proteins were upregulated and 17 proteins were downregulated in L24 when compared with D24. The results depict the comparative protein expression in R. sphaeroides mediated through growth under light or dark conditions. The data suggest that the overexpressed proteins, phosphoribosyl-ATP pyrophosphatase (HisE), in the D24/aerobic culture are involved in the positive regulation of PAC production can be functionally applied in metabolic engineering and industrial processes.
Keywords: Comparative proteomics; Metabolic characteristics; Photosynthesis; Proteomic responses; Rhodobacter sphaeroides; Two-dimensional gel electrophoresis.