Biology > Bacteria > Isolation of hydrocarbon-degrading bacteria

Site: http://www.nexusresearchgroup.com/microbiology/hcmicrobes.htm

Grade Category: High School

Subject Category: Biology

Sub Category: Bacteria

Isolation of hydrocarbon-degrading bacteria:


1. Environmental samples are diluted as above. Portions (0.1 mL) of each dilution are spread onto BH agar and supplied with hydrocarbons as sole carbon and energy source by placing it in a vapour tube (cut off micropipette tips, sealed at one end with heat) in the lid of the plate. As a hydrocarbon source it suggested you first try jet fuel or pure compounds like naphthalene (just place a few crystals in the lid of the plate) or dodecane. For jet fuel and dodecane place about 20 ┬ÁL on filter paper in the lid of the dish or use vapour tubes.

2. Control plates without substrate are also inoculated.

3. Seal all plates with parafilm and then incubate in a tupperware box (to reduce loss of volatile hydrocarbons in to the lab). All plates are prepared in triplicate for each dilution and incubated at 25oC for at least 1 month.


Colonies larger and different from those on the substrate-free control plates are selected and purified for further investigation. Hydrocarbon-degrading bacteria are removed from the isolation plates and purified on BH plates supplied with hydrocarbons as sole source of carbon.

(Original protocol courtesy of Dr Jackie Aislabie)