Procedure for the examination of bacterial capacity to accumulate poly-beta-hydroxybutyrate inclusions. Used
mainly for Pseudomonas and Pseudomonas-like organisms.
Cultures are grown in a medium with high carbon-nitrogen ratio.
Sudan black solution is prepared as 0.3% solution in 70% ethanol, shaken and
allowed to stand overnight.
Make a smear from the culture, dry and heat-fix it then flood it with Sudan black
solution and wait 15 minutes.
Drain off excess stain, dry the slide, then rinse in water and dry again.
Counterstain with safranin, rinse and dry. Examine with oil immersion microscope.
Poly-beta-hydroxybutyrate inclusions are stained blue-grey to black. Result
may vary depending on strain tested: Acidovorax or Burkholderia strains give
weaker reaction than Ralstonia.
1. Pseudomonas Pathogens of Stone Fruits and Nuts: Classical and Molecular Phytobacteriology. COST873 ESR
Training Course Handbook and Presentations. 6th-9th April 2010, Belgrade,Serbia.
(c) Costin Stoica