The mutant sub strain of Bacillus subtilis has the ability to remove ammonium in a RAS trout system

BACKGROUND AND OBJECTIVESThe purpose of this research was to apply mutant substrains of Bacillus subtilis with high ability to remove ammonium and use in trout culture water under cold and laboratory conditions.MATERIALS AND METHODSThe effective dose of ۵.۸ kGy of the Bacillus subtilis strain was achieved by gamma radiation. Then ۲۰۰ colonies were randomly selected and numbered. The potential for ammonium removal was investigated separately in the selected colonies. After the screening steps, the selected strains were adapted to cold temperatures. The biofilter water of a RAS trout system was prepared and the selected mutant substrain number ۱۸۰ with a dilution of ۱۰۸ CFU/ml was added to the trout RAS biofilter water and the ammonium concentration was evaluated.RESULTS AND DISCUSSIONIn this study, Bacillus subtilis mutants were subjected. During fish farming, the system RAS moves towards nitrifying bacteria that have adapted to the system. Biofilters play an essential role in these systems and the most common microbial communities in these systems include Nitrosomonas sp., Nitrospira spp. Nitrobacter sp. and Bacillus. In this study, we report a strategy for biofortification of RAS biofilters enriched with a mutant substrain of heterotrophic bacteria. With this substrain, we achieved an improvement in ammonium removal compared to conventional communities in biofilters at ۹ and ۱۵ °C.CONCLUSIONBacillus subtilis substrain number ۱۸۰ has been proposed as an effective ammonium-degrading microorganism in trout fish RAS.

کلیدواژه ها:

Bacillus Subtilis ، Mutation ، Ammonium Oxidizing Bacteria ، Cold Adaptation