Enumeration of Total Virioplankton and Isolation of Specific Cyanophages from Selected Aquatic Ecosystems in Goa, India

Viruses are known to be highly abundant and, therefore, ecologically significant entities of all aquatic ecosystems. However, very few studies from marine and freshwater ecosystems in India have dealt with enumeration, isolation or characterization of their virus (virioplankton) populations. In the present study, we have estimated total virioplankton populations from several kinds of aquatic niches, viz. rice fields, lakes and estuaries, using flow cytometry. Rice field floodwaters displayed the highest virioplankton count of 1.21 × 10⁷ particles per ml. As cyanophages form the second most abundant class of virioplankton (after bacteriophages), we also isolated four cyanophages from the same aquatic niches.