Tennessee Wastewater Operator Practice Exam

Microorganisms in a biofilm utilize which of the following to convert particulate BOD into soluble BOD?

1. Acids

2. Enzymes

3. Proteins

4. Cellulose

The correct answer is: Enzymes

Microorganisms in a biofilm convert particulate biochemical oxygen demand (BOD) into soluble BOD primarily through the production and secretion of enzymes. These enzymes act as biological catalysts, breaking down complex organic materials into simpler, soluble forms that can then be easily assimilated by the microorganisms for metabolism. Enzymes are specific in their function; they can target different types of organic compounds, such as carbohydrates, lipids, and proteins, facilitating their transformation into forms that can be absorbed by the microbial cells. This enzymatic action is critical for the initial steps of wastewater treatment, as it enhances the overall efficiency of the microbial community by increasing the available organic matter that can be utilized. In this context, while acids, proteins, and cellulose all play roles in microbial metabolism or are part of the organic material present in wastewater, they do not directly assist in the conversion process from particulate BOD to soluble BOD in the same strategic manner that enzymes do. Thus, the focus on enzymes highlights their essential role in microbial digestion within biofilms.