Rhodobacter capsulatus is a versatile organism capable of growing on different growth conditions including photofermentation in the presence of carbon source, aerobic respiration, anaerobic respiration in the presence of an external electron acceptor such as DMSO. The photofermentative growth of R.capsulatus results in hydrogen production which stands out as an environmentally harmless method to produce hydrogen and accepted as one of the most promising process. Due to the serious problems such as as global climate change and environmental pollution caused by the fossil fuels, there is an increasing requirement for a clean and sustainable energy source. Furtherrmore, the ability of R.capsulatus to fix nitrogen, to use solar energy makes it a model to study various aspects of its metabolism. Thus the goal of this study is to increase the potential in biohydrogen production with the photofermentative bacteria and to investigate the proteins playing roles in different growth modes of the bacteria. In the present study, protein profiles of Rhodobacter capsulatus grown on respiratory, anaerobic respiratory and photofermentative growth modes were obtained. LC-MS/MS system is used to analyze the proteome as a high throughput technique. Physiological analysis such as HPLC for the analysis of the carbon source consumption, GC and analysis of pigments were carried out to state the environmental conditions. As a result, total of 460 proteins were identified with 17 proteins being unique to particular growth condition. Ratios of the proteins in different growth conditions were compared and important proteins were highlighted.