Generally peudomonas aeruginosa appear colourless in mac media since it is a non lactose fermenter, but after around a week I m observing that the colour of my pseudomonas culture in mac media has changed to pink? What can be the reason for this?
Pseudomonad pigments including pyocyanin are not pink.
The pink is most probably due to due to pH change/acid production. MacConkey is read after 48 hours. What happens subsequently has apparently not been studied.