A dead-end filtration method to remove particle-associated pathogens in aquaculture systems

Abstract

To reduce the incidence of bacterial diseases in recirculating aquaculture systems, 27 marine bacterial species were introduced into Instant Ocean maintained at 25A degrees C. Those species were enumerated before and after filtration to evaluate the efficiency of the filtration procedure. The effects of sari filter and nylon filter on the survival of sea bass challenged with Vibrio alginolyticus were also determined. The results of laboratory studies indicated that the ability to remove pathogens was typically 1-3 log orders. Above 90% Vibrio sp., i.e., which were attached to particles, were removed by either 20-mu m nylon net or four layers of sari. A 9.53% mortality of sea bass was reported in pilot filtration test using sari material as an end filter, while this percentage increased to 33.35% in control groups. It is concluded that a simple filtration procedure that involves the use of four-layer sari material can reduce the numbers of pathogens attached to particles in aquaculture system. The results of this study provide the basis for pathogen reductions in full-scale facilities.