Tennessee Wastewater Operator Practice Exam

What do acidogenic bacteria primarily convert in anaerobic digestion?

1. Complex organic materials

2. Sugars into alcohol

3. Soluble organic compounds into VFAs

4. Inorganic materials into biogas

The correct answer is: Soluble organic compounds into VFAs

Acidogenic bacteria play a crucial role in the anaerobic digestion process by converting soluble organic compounds into volatile fatty acids (VFAs). This conversion is essential because it occurs during the initial stages of anaerobic digestion, where complex organic materials are broken down into simpler forms. During this fermentation process, these bacteria utilize various soluble organic substrates, including carbohydrates, proteins, and fats, and transform them into VFAs, hydrogen, and carbon dioxide. The production of VFAs is significant as it provides the necessary substrates for the subsequent groups of bacteria, specifically acetogenic and methanogenic bacteria, which further convert VFAs into methane and carbon dioxide, the final products of anaerobic digestion. In summary, acidogenic bacteria are vital for breaking down soluble organic compounds, leading to the formation of VFAs, which are necessary for the overall digestion process in anaerobic systems.