Mold Remediation Certification Practice Exam

Which type of bacteria is commonly associated with sewage?

1. Gram-positive

2. Gram-negative

3. Spore-forming

4. Aerobic

The correct answer is: Gram-negative

The correct choice is indicative of the characteristics of bacteria typically found in sewage systems. Gram-negative bacteria are known to be prevalent in environments with high organic material, such as sewage. This group of bacteria has a thin peptidoglycan layer and an outer membrane, which not only aids in their survival in harsh conditions of sewage but also contributes to their pathogenic potential. Many species within this category, such as Escherichia coli and Salmonella, are commonly associated with waterborne illnesses arising from contaminated sewage, thus underlining their significance in discussions of public health and environmental safety. In contrast, while Gram-positive bacteria do reside in various environments, they are less commonly found in sewage due to their preference for different types of organic material and conditions. Similarly, spore-forming bacteria and aerobic bacteria can also be found in sewage but do not specifically define the predominant bacterial populations present in wastewater. Thus, focusing on Gram-negative bacteria provides a clearer connection to the risks and concerns associated with sewage contamination.