Effect of Metazoa on Proportion of Physiologically Active Bacteria.

Effect of metazoa Philodina erythrophthalma on proportion of physiologically active bacteria was evaluated using two fluorescein chemicals 6CFDA (6-Carboxyfluorescein diacetate) and DAPI (4', 6-diamidino-2-phenylindole) for staining bacteria. 6CFDA stains bacteria with esterase hydrolyzing activity. DAPI stains DNA of bacteria (indicator of total bacteria) . The number of bacteria in the presence of P. erythrophthalma was lower comparing with those in the absence of P. erythrophthalma. But the decrease of active bacteria is smaller than that of total bacteria, enhancing proportion of active bacteria (number of active bacteria divided by number of total bacteria) from 40% in the absence of P. erythrophthalma to 46% in the presence of P. erythrophthalma. Proportion of active bacteria in flocculated bacteria tended to be higher in the presence of P. erythrophthalma comparing with that in the absence of P. erythrophthalma.