Effect of Sanitizer Treatment on Bacteriology of Microcosm Simulating Shrimp Pond Ecosystem

Abstract

The effect of three commonly used water sanitizers, viz benzalkonium chloride (BKC), sodium hypochlorite and iodophor on shrimp pond associated microbiota was studied in laboratory microcosms. Treatment of microcosm with 0.1 ppm BKC did not lower the total heterotrophic bacterial count. With 3.0 ppm, there was an initial reduction of one log unit at 8h followed by an increase in bacterial counts at 18h. Ammonia oxidizers on the other hand were affected even with 0.1 ppm. Sodium hypochlorite at 10 ppm brought about one log reduction in heterotrophic bacterial count and the level of ammonia oxidizers was also reduced. Treatment with 10 ppm iodophor did not affect both autotrophic and heterotrophic bacteria. The results suggest that sanitizers should be used with caution in shrimp ponds due to their deleterious effect on useful microorganisms involved in mineralization.