Application of Flow Cytometry for Measuring Changes in Intracellular RNA Contents of Marine Bacteria

Abstract

A flow cytometer was used to measure the intracellular RNA contents of Vibrio alginolyticus and natural bacterial populations after specific staining with acridine orange. During the course of starvation, the RNA level in Vibrio alginolyticus gradually decreased, whereas subsequent enrichment caused a rapid increment of RNA and resulted in the appearance of a distinct group on the cytometric histogram. Similar distinct subpopulations were also confirmed in natural seawater samples after 6 hours direct viable count (DVC) incubation. Moreover, it was confirmed that the DVC technique enabled us to detect and enumerate marine bacteria using 16S rRNA fluorescent oligonucleotide probes.