Biodegradation of 2-Methylisoborneol (2-MIB) by Single-Bacterium Isolations from Biological Filters in Drinking Water Treatment Plants

Excessive taste and odor compounds, such as 2-methylisoborneol (2-MIB), significantly impact the potability of water and are difficult to be removed by conventional water treatment units. In this study, three strains of bacteria were isolated from a biological filter in a drinking water treatment plant, which achieved high 2-MIB removal efficiency over 9 months. The three isolates demonstrated high 2-MIB degradation efficiency (>60%) in the environment with both high (500 ng/L) and low (100 ng/L) 2-MIB concentrations. The bacterial growth and the 2-MIB removal of the three isolates were studied at different temperatures, pH, and NaClO dosages. The xenobiotic-degradation-related functional genes relevant to the possible degradation of 2-MIB were profiled and linked with the four reported degradation pathways, including dehydration, demethylation, C-C bond cleavage, and conjugation. With the understanding of 2-MIB-related xenobiotic degradation functional genes, the gene-editing technology can be used to develop engineered plasmids, which could potentially be applied to different environments for the enhancement removal of 2-MIB.