Bacterial flora analysis of a microbial mat clogging the pipes of a well

Abstract When groundwater rich in dissolved ferrous ion [Fe(II)] is pumped from wells, iron-oxidizing bacteria can grow and clog the well’s screens, pipes, and pumps, making it difficult for the pump to operate fully. In this study, we employed 16S rRNA gene amplicon sequencing to investigate the types of microorganisms that adhere to a well’s pipes and identified the main bacterial species involved in the microbial mat and clogging process. Deposits from the sampling equipment were collected daily for seven consecutive days and subjected to 16S rRNA gene amplicon sequencing, revealing the continuous presence of a Gallionella sp. We speculated that this species was the initial factor in the microbial mat’s formation and hypothesized that Gallionella forms long thread-like "stalks” and attaches to the pipe’s inner surface; as the stalks accumulate and become intertwined, they create a mat. As the mat continues to grow without detaching from the pipe’s inner surface even under rapid water flow, the pipe eventually clogs.