I was trying out different transformation protocols on Pseudomonas putida and a wt Alcaligenes. The vector I was using was pSF-OXB15 with a chromoprotein (amilcp) as a marker. I've used this same vector to transform E.coli successfully many times. However, when I transform other bacteria the bacteria grow (they express the resistance gene to kanamycin) BUT they don't turn purple. I'm not sure why. Does anyone have any tips for troubleshooting chromoprotein expression?