Occurrence and phylogenetic analysis of Pseudanabaena sp. producing
2-methylisoborneol in drinking water source of South Korea
We investigated the abundance of Pseudanabaena species and the
concentration of the monoterpene 2-methylisoborneol (2-MIB) from July to
October at three sampling sites in South Korea. To identify the main
cause of 2-MIB occurrence in drinking water source, we characterized and
performed a phylogenetic analysis of the 2-MIB synthase gene.
Pseudanabaena was the dominant cyanobacterium (68–100%) among
the samples. At all three sampling sites, a strong positive correlation
was detected between 2-MIB concentrations and Pseudanabaena cell
numbers. A phylogenetic analysis of 222 MIB sequences isolated from the
water samples showed that all of the clones were affiliated with the
Pseudanabaena MIB synthase gene, demonstrating that the 2-MIB in
Han River drinking water source was produced by Pseudanabaena sp.
Using a clone of the 2-MIB gene, network-based analysis and unweighted
pair group method with arithmetic mean (UPGMA) analysis were used to
examine temporal and spatial variation in the 2-MIB concentration and
Pseudanabaena abundance. The network analysis showed greater
temporal than spatial similarity among the 2-MIB gene clones. Together,
our results demonstrate that Pseudanabaena was the main producer
of 2-MIB. These findings provide important information for odor
management in drinking water source.