Now, which species of Pseudomonas are you interested in and is it a particular
c-type cytochrome or the whole range? Pseudomonas stutzeri and Pseudomonas
aeruginosa both make a wide range of c-type cytochromes.
If you're interested in spectroscopy of several of them, the easiest approach
is to make a total soluble extract or a periplasmic fraction by
spheroplasting, load onto a large ion-exchange column (e.g. DEAE cellulose)
and run a NaCl gradient (say 0-400mM). Cytochromes c will elute as coloured
fractions at various points and this is often enough for a crude spectrum. You
can clean up any of particular interest by another step, such as a gel
I can supply further details if you're a bit more specific.