What part of an aircraft fuel system can experience issues due to microbial activity?

Microbial activity, particularly from bacteria and fungi, can lead to biofilm formation and the growth of biomass in aircraft fuel systems. This is especially problematic in fuel tanks where water can collect at the interface between fuel and water. The presence of moisture provides an ideal environment for microorganisms to thrive, resulting in the formation of sludge or other byproducts that can contaminate the fuel. This contamination can lead to corrosion, clogging, and a variety of performance issues within the entire fuel system.

Fuel tanks are prone to these issues because they often contain stagnant fuel and moisture, enabling microbial growth that can adversely affect fuel quality. Contamination from this microbial activity may then spread to other components like fuel lines, pumps, and filters, but it originates in the fuel tanks where microbial growth is most likely to occur.