Petroleum as a Microbial Food Source Some microorganisms of the genera Nocardia and Pseudomonas can grow in an environment where hydrocarbons are the only food source. These bacteria oxidize straight-chain aliphatic hydrocarbons, such as octane, to their corresponding carboxylic acids: CH(CH) CH3 + NAD+ + OCH(CH),COOH + NADH + H+ How could these bacteria be used to clean up oil spills? What would be some of the limiting factors to the efficiency of this process?