Efficacy of BioRas® Balance (an enzyme product) to break down hydrogen peroxide following routine treatment applications in aquaculture

Authors: MAY, TRAVIS - Freshwater Institute; GOOD, CHRISTOPHER - Freshwater Institute; REDMAN, NATALIE - Freshwater Institute; VINCI, BRIAN - Freshwater Institute; XU, FENG - Novozymes; ØSTERGAARD, LARS HENRIK - Novozymes; MANN, KEVIN - Novozymes

Submitted to: Aquaculture Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2022
Publication Date: 6/4/2022
Citation: May, T., Good, C., Redman, N., Vinci, B., Xu, F., Østergaard, L., Mann, K. 2022. Efficacy of BioRas® Balance (an enzyme product) to break down hydrogen peroxide following routine treatment applications in aquaculture. Aquaculture Research. https://doi.org/10.1111/are.15927.
DOI: https://doi.org/10.1111/are.15927

Interpretive Summary: Fish farmers using water recirculation aquaculture systems (RAS) would significantly benefit from advances in therapeutic treatment approaches that are both efficacious in fighting disease and safe for RAS biofilter function. Hydrogen peroxide is currently FDA-approved for use in aquaculture to treat specific diseases; however, at therapeutic concentrations peroxide will compromise biofilter function. We therefore evaluated a novel enzymatic product to break down peroxide following culture tank static bath treatment, after which recirculation water flow through a biofilter would normally be resumed. We also examined enzymatic break down of peroxide following system disinfection and prior to discharge of system water. We determined that the enzymatic product (BioRas® Balance) was effective at quickly reducing peroxide to safe concentrations, in either post-static bath therapeutic application or post-system disinfection situations. Our results are encouraging for RAS farmers who would benefit from methods to break down peroxide and avoid potentially detrimental post-treatment or post-disinfection consequences.

Technical Abstract: Application of water treatments and therapeutants in recirculating aquaculture systems (RAS) is complicated by potentially detrimental secondary impacts on critical nitrifying bacterial populations present in biofilters, leading to reduced total ammonia nitrogen (TAN) and nitrite-nitrogen oxidation. Hydrogen peroxide (H2O2), while U.S. Food & Drug Administration-approved for use in aquaculture under specific conditions, and while considered environmentally benign due to formation of non-toxic decomposition end-products, is known to negatively impact biofiltration when applied at therapeutic concentrations in RAS. The ability for RAS producers to use therapeutic or disinfection-level H2O2 concentrations in culture tank static bath treatments, followed by decomposition of H2O2 prior to resumption of recirculating water flow through biofilters, would be advantageous. We therefore sought to assess H2O2 decomposition using a novel enzymatic product following static bath applications of H2O2 at both therapeutic- and disinfection-level concentrations. Under the conditions of our studies, we determined that the enzymatic product (BioRas® Balance) was effective at quickly reducing H2O2 to safe concentrations, in either post-static bath therapeutic application or post-system disinfection scenarios. Hydrogen peroxide decay curves over a range of catalase concentrations are presented, as well as derived first-order reaction constants and formulae. At 10 mg/L, the enzymatic product was able to eliminate H2O2 after 10 minutes in both therapeutic and disinfection application scenarios. Overall, the results of these experiments are encouraging for RAS farmers who may require utilizing H2O2 at concentrations that would normally compromise biofilter nitrification processes.