|Liu, Dibo - Leibniz Institute Of Freshwater Ecology And Inland Fisheries|
|Behrens, Sascha - Leibniz Institute Of Freshwater Ecology And Inland Fisheries|
|Pedersen, Lars-flemming - Technical University Of Denmark|
|Straus, David - Dave|
|Meinelt, Thomas - Leibniz Institute Of Freshwater Ecology And Inland Fisheries|
Submitted to: Aquaculture Report
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2016
Publication Date: 9/23/2016
Publication URL: http://handle.nal.usda.gov/10113/5578401
Citation: Liu, D., Behrens, S., Pedersen, L., Straus, D.L., Meinelt, T. 2016. Peracetic acid is an optimal disinfectant for fish-microalgae integrated multi-trophic aquaculture systems. Aquaculture Report. 4:136-142. Available:http://www.sciencedirect.com/science/article/pii/S2352513416300977.
Interpretive Summary: Systems that contain fish and algae have been shown to be of interest to the aquaculture industry. Waste form the fish can be used to grow the algae and the algae provides oxygen and can be used for fish fees ingredients or biofuel. But, a disinfectant must also be used to control possible pathogens in the system. Peracetic acid (PAA) is a mixture of acetic acid (concentrated vinegar), hydrogen peroxide and water that is considered a safe disinfectant because it degrades to harmless ingredients. We evaluated PAA products with proportions of PAA and hydrogen peroxide for their effects on the growth and photosynthesis of saltwater algae. We found that PAA products with low proportions of hydrogen peroxide could be better disinfectants without damaging the metabolism of the algae.
Technical Abstract: Integrated multi-trophic aquaculture is a promising direction for the sustainable development of aquaculture. Instead of releasing nutrition-rich waste to the environment or decomposition of nutrients via the biofilter, the ‘waste’ from fish can be recycled to produce byproducts (e.g., algae, plants etc.). Microalgae have good potential to be integrated with aquaculture because they can use the nitrogen excreted from fish and share the same optimal pH value as in aquaculture. As a byproduct, the microalgae biomass can be used for fish feed or biofuel. However, the microalgae-fish integrated aquaculture system has a simultaneous threat from fish pathogens and phytoplankton-lytic bacteria. Therefore, it is necessary to apply proper disinfectants as prophylaxis or treatment which are effective against these threats, but safe to fish and microalgae. For this purpose, peracetic acid (PAA) is a valid option because it is highly effective against fish pathogens and bacteria at low concentrations and degrades spontaneously to harmless residues. In the present study, we exposed the marine microalgae Tetraselmis chuii once per day for four days to four PAA products with differing hydrogen peroxide (H2O2) proportions at two concentrations (1 and 2 mg L-1 PAA). The H2O2 solutions at equivalent total peroxide concentrations were tested in parallel. The results show that the growth and photosynthesis of T. chuii were not affected by three of the PAA products (Wofasteril® E400, Wofasteril® E250 and Applichem® 150) and equivalent H2O2 solutions at both concentrations. In contrast, Wofasteril® Lspez and an equivalent H2O2 solution at both concentrations, caused irreversible culture collapse, photosynthesis dysfunction and irreversible cell damage. In conclusion, PAA products with low proportions of H2O2 are optimal disinfectants for fish-microalgae integrated multi-trophic aquaculture systems.