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 25°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-lm 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.

A predictive model ofVibrio choleraefor combined temperature and organic nutrient in aquatic environments

“…The composition of this wastewater was described previously (Fu et al . ). Sucrose (C 12 H 22 O 11 ) was used as a carbon source to control the concentration of COD from 5 to 40 mg l −1 .…”

“…Vibrio cholerae NE‐9 or V. cholerae NE‐1 was grown in 100 ml of LB broth in 250 ml flasks, and starvation of cells was ensured using procedures described in Fu et al . . Starved cells were added to sterilized aquaculture sea water with different COD concentration to a final concentration of 10 5 CFU ml −1 and then were stored at 10° for 18 h (for V. cholerae NE‐1, cells were added to natural sea water).…”

“…Sterilized aquaculture sea water, comprising fish faeces and unconsumed feed, was used as a substrate solution for the growth of V. cholerae NE-9 (salinity level is 2Á7%). The composition of this wastewater was described previously (Fu et al 2012). Sucrose (C 12 H 22 O 11 ) was used as a carbon source to control the concentration of COD from 5 to 40 mg l À1 .…”

Influence of a membrane‐denitrification reactor on the microbial community of an aquaculture recirculation system

“…A reduction in bacterial numbers can be achieved by removing organic particles from the water during the filtration process (Ray et al., ) or by the filtration itself. This could be achieved even by simple filtration methods with a 20‐μm nylon net or a four‐layer sari material as filter (Fu, Shen, Chen, Tu, & Liu, ). The pore size of the membrane used in the present study was 0.03–0.1 μm, and a direct filtration of bacteria and organic particles was therefore probable.…”

“…A reduction in bacterial numbers can be achieved by removing organic particles from the water during the filtration process (Ray et al, 2010) or by the filtration itself. This could be achieved even by simple filtration methods with a 20μm nylon net or a four-layer sari material as filter (Fu, Shen, Chen, Tu, & Liu, 2012).…”