In vivo characteristics and localisation of carotenoid pigments in psychrotrophic and mesophilic Micrococcus roseus using photoacoustic spectroscopy.

Photoacoustic spectra of cells of M. roseus were recorded to study the in vivo characteristics and localisation of the carotenoid pigments in these cells. The PA spectra indicated that both the psychrotrophic and mesophilic strains had similar chromophores. The cis carotenoids were prominent in the psychrotrophic M.roseus whereas shorter polyenes were more prominent in mesophilic M.roseus. Further, depth profiling photoacoustic studies revealed that in both the strains of M.roseus the bulk of the chromophore was associated with the cell membrane.