Establishment of a real-time PCR method for quantification of geosmin-producing Streptomyces spp. in recirculating aquaculture systems

Establishment and field applications of real-time PCR methods for the quantification of potential MIB-producing cyanobacteria in aquatic systems

“…Considering the volume of samples collected, the limit of quantification (LOQ) of these qPCRs should be at the level of 10 3 copies L −1 in field, and this LOQ was verified in the practical monitoring of the three waters. Unlike the qPCR assays targeting geosmin-producing Streptomyces (Auffret et al 2011) and Anabaena (Su et al 2013;Tsao et al 2014) based on SYBR Green, the qPCR methods developed in this study introduced TaqMan technique, which has a high specificity (Savichtcheva et al 2011;Srivastava et al 2013), to quantify odor-producing organisms. To our knowledge, this study is the first report of qPCR assays to detect and quantify potential MIB-producing cyanobacteria.…”

“…Previous studies have revealed that filamentous cyanobacteria species are the main biological source of odorous MIB and geosmin aquatic ecosystems, especially in eutrophication waters (Izaguirre and Taylor 2004;Jüttner and Watson 2007;Smith et al 2008;Watson et al 2008), and actinomyces (mainly as Streptomyces) are usually found as dominant geosmin-producing organisms in the sediment or recirculating aquaculture systems (Zuo et al 2010;Auffret et al 2011). This study indicated that cyanobacterial mic genes were detected and quantified in most investigated water samples, and MIB-producing Streptomyces were identified scarcely, thereby confirmingthat MIB is mainly cyanobacteria originated in Lushui Reservoir, Donghu Lake, and Qinghai Lake.…”

“…Taste and odor (T&O) episodes caused by 2-methylisoborneol (MIB) and geosmin (trans-1,10-dimethyl-trans-9-decalol) have been reported worldwide in diverse waters, such as lakes, fish ponds, and reservoirs (Jüttner and Watson 2007;Li et al 2007;Watson et al 2007Watson et al , 2008Auffret et al 2011;Su et al 2013;. These two musty-earthy monoterpene and sesquiterpene metabolites are exceptionally sensitive for humans and have a low sensory threshold of 2 to 10 ng L −1 (Cook et al 2001).…”

“…To prevent the problems associated with T&O events in drinking water catchments, sensitive and effective methods for the detection of MIB represent a valuable tool (Watson et al 2008;Dzialowski et al 2009). A wide variety of microorganisms, including cyanobacteria, actinomycetes, fungi, and myxobacteria, can synthesize and secrete MIB as a secondary metabolite (Jüttner and Watson 2007;Komatsu et al 2008;Auffret et al 2011), but cyanobacteria species are regarded as the main MIB producers in freshwater ecosystems where photosynthetic growth occurs (Watson 2004;Jüttner and Watson 2007). Thus, the detection and quantification of MIB genes in cyanobacteria could be a valuable indicator for the development of T&O events in natural waters.…”

“…The typical advantages of qPCR, including sensitivity, speed, and reliability for the large-scale quantification of corresponding cyanobacterial biomass on-site, have been proven (Ha et al 2009;Srivastava et al 2013;Wang et al 2013). qPCR methods have also been used to measure geosmin-producing Streptomyces and Anabaena species, and studies have exhibiteda positive correlation between the abundance of gene copies and the corresponding geosmin concentrations (Auffret et al 2011;Su et al 2013;Tsao et al 2014). Kutovaya and Watson (2014) and Suurn kki et al (2015) developed polymerase chain reaction (PCR) protocols to detect cyanobacterial MIB/geosmin producers.…”