Improvement of waterborne using Dyadobacter sp. (No. 68) and Janthinobacterium sp. (No. 100) bacteria and comparing the hematological indices in a recirculating rainbow trout (Oncorhynchus mykiss) culture system

Targeted use of ammonia and nitrite degrading bacteria could increase the efficiency of the closed recirculating fish culture systems. Ammonia and nitrite assimilation by heterotrophic bacteria are important along with autotrophic species. The purpose of this study was to investigate the use of two strains of nitrifying bacteria Dyadobacter sp. (no. 68) and of Janthinobacterium sp. (no. 100) in the rainbow trout breeding system. These two types of bacteria with a dilution of 8×109 cfu (A) in a 1000 ml container transferred into 400 liter fish or experimental tanks containing 50 pieces Trout 50.65±3.89 g, also one treatment was considered as control group [n=3] (C). After 10 days, hematological and qualitative indices of water in rainbow trout were investigated. The results showed that the concentration of ammonia in the experimental group containing these two types of bacteria was lower and the nitrite and nitrate in this group were higher than the control group. The hematological indices in the control group did not show any significant changes from baseline, whereas in the control group hematological indices decreased. It was concluded that Dyadobacter sp. (no. 68), Janthinobacterium sp. (No. 100) were usable to assimilate ammonia and nitrite in the rainbow trout system. Finally, it can be concluded that the use of these two strains could have a positive effect on improving the quality of the environment and consequently on physiological conditions in the rainbow trout system.