FCM analysis were performed in water samples and elutriates using a commercial kit (Bacteria Counting Kit, Molecular Probes™, Invitrogen) for accurate enumeration of bacteria. The manufacturer’s protocol was strictly followed for further analysis of the samples in an Attune® Acoustic Focusing Cytometer (TermoFisher Scientific) equipped with a 488nm laser. In short, collected samples were added SYTO BC and the mixture was incubated at 37°C during at least 5min; then,themicrospherestandardsuspensionwasaddedtothestainedcell preparation andthis sample underwent FCM reading. The SYTO BC was excited at 488nm and fluorescence measured with 530/30 bandpass filter(BL1).