What is the breakdown of heavier oil to a lighter hydrocarbon by bacterial action?

• A. Biodegration
• B. Biodegradation
• C. Fermentation
• D. Catalysis

Answer: (A)

Biodegradation is the breakdown of complex oil molecules by microorganisms, including bacteria, into simpler substances. In heavier oil, certain bacteria use the long-chain hydrocarbons as carbon and energy sources, employing enzymes to oxidize and cleave carbon–carbon bonds. This enzymatic action progressively shortens chains and creates lighter hydrocarbons, with end products ranging from simpler hydrocarbons to CO2 and water under aerobic conditions (and other products under anaerobic conditions). The process relies on microbial metabolism and can be influenced by factors like temperature, nutrient availability, and oxygen presence. This is why biodegradation is the correct concept here—fermentation describes sugar breakdown to alcohols or acids, catalysis is a chemical acceleration not driven by microbes, and the correct term is biodegradation (note the standard spelling).