PROPHAGE INDUCTION OF INDIGENOUS MARINE LYSOGENIC BACTERIA BY ENVIRONMENTAL-POLLUTANTS

Lysogenic bacteria may be abundant components of bacterial assemblages in marine waters. The tremendous number of viruses found in estuarine and other eutrophic environments may be the result in part of inducti on of prophages. Mitomycin C is the inducing agent of choice for proph age induction; however this is not naturally found in the marine envir onment. We determined the capability of environmentally important poll utants to effect prophage induction in natural populations of marine b acteria. We investigated Aroclor 1248, a PCB mixture, bunker C fuel oi l #6, and a pesticide mixture as inducing agents for natural bacterial communities from the Gulf of Mexico. Mitomycin C was also employed as a positive control for induction. Induction was determined as a signi ficant increase in viral direct counts compared to control and ranged from 149 to 1336% of the controls. Two-thirds of the environments samp led showed prophage induction by one of the methods utilized, with the PCB mixture and Aroclor 1248 giving the highest percent efficiency (7 5%) of induction. This study shows that many environmentally important pollutants may be inducing agents for natural lysogenic viral product ion in the marine environment.