In the present studies, respiratory chain pathogenic bacterium, Proteus mirabilis, was investigated. In the first phase, growth profile study was performed to optimize the P. mirabilis growth. Maximum bacterial growth could be obtained between 10 – 12 h of culturing time. Down-stream processing was performed by using sonication, ultracentrifugation and detergent solubilization techniques. Partially purified respiratory contents were analyzed spectrophotometrically. Pyridine-ferrochrome and redoxspectra showed the presence of heme-c