Microbial interactions responsible for dissolved DNA production in a hypereutrophic pond

Concentration of dissolved DNA, microbial biomass, and consumption of bacte ria by heterotrophic nanoflagellates (HNF) and ciliates were examined in a hypereutrophic pond for over 7 months to elucidate the main factors which i nfluenced the release of dissolved DNA. Changes in concentration of dissolv ed DNA correlated well with both abundance of ciliates (r = 0.788, p < 0.01 ) and rotifers. (r = 0.738, p < 0.01). A significant correlation was also f ound between dissolved DNA concentration and ciliate community ingestion ra tes (r = 0.668, p < 0.01). These results suggest that consumption of bacter ia by ciliates is an important reason for the release of dissolved DNA.