An alternative method to quantify 2-MIB producing cyanobacteria in drinking water reservoirs: Method development and field applications

Abstract

2-Methylisoborneol (2-MIB) is a commonly detected cyanobacterial odorant in drinking water sources in many countries. To provide safe and high-quality water, development of a monitoring method for the detection of 2-MIB-synthesis (mibC) genes is very important. In this study, new primers MIBS02F/R intended specifically for the mibC gene were developed and tested. Experimental results show that the MIBS02F/R primer set was able to capture 13 2-MIB producing cyanobacterial strains grown in the laboratory, and to effectively amplify the targeted DNA region from 17 2-MIB-producing cyanobacterial strains listed in the literature. The primers were further coupled with a TaqMan probe to detect 2-MIB producers in 29 drinking water reservoirs (DWRs). The results showed statistically significant correlations between mibC genes and 2-MIB concentrations for the data from each reservoir (R²=0.413-0.998; p<0.05), from all reservoirs in each of the three islands (R²=0.302-0.796; p<0.01), and from all data of the three islands (R²=0.473-0.479; p<0.01). The results demonstrate that the real-time PCR can be an alternative method to provide information to managers of reservoirs and water utilities facing 2-MIB-related incidents.

Keywords: 2-MIB-synthesis gene (mibC gene); 2-methylisoborneol (2-MIB); Cyanobacteria; Real-time PCR; Taste and odor.