Intensive farming conditions in aquaculture not only allow for a higher number of shrimp production but also result in high levels of metabolic waste and unconsumed feed, which affect the water quality in breeding environments.
An innovative approach to control nitrogen compounds is bioremediation, including the bioaugmentation of nitrifying bacteria in the aquaculture environment.
Various studies have reported that Pseudomonas sp. exhibits nitrification activity, being able to oxidize ammonia into nitrites and nitrates.
A team of researchers from IPB University and the National Research and Innovation Agency (BRIN) determined the effectiveness of inoculating Pseudomonas sp. with different densities in the cultivation of Litopenaeus vannamei shrimp.
Application of nitrifying bacteria
The Pseudomonas sp. bacteria was isolated from seawater in Ancol (Jakarta). Bacterial cultures with densities of 107, 108, and 109 CFU mL−1 in a volume of 100 mL were applied to the water in the breeding tanks.
Cultivation water quality
The water quality parameters remained within the accepted range for shrimp growth during the 8-week cultivation period. However, the pH in the control group and the 107 CFU mL-1 treatment were below the optimal level compared to the other treatments.
“The TAN concentration, consisting of NH3 and NH4+, did not show significant differences among the treatments from weeks 0 to 6 but was significantly different in week 8,” they reported.
Furthermore, they highlight that the TAN concentration in the bacterial application treatment was lower than in the control. The nitrifying bacteria Pseudomonas sp. uses NH4+ as its nutrient source.
The NO2– levels did not show significant differences among all treatments from week 0 to 8. NO2– in all treatments increased until week 4 and declined in week 6.
The nitrification process through microbial activity produces NO3- as the end product. The high level of NO3– in the 109 CFU mL-1 treatment indicates that nitrification was faster than in the other treatments.
“These results show that the application of nitrifying bacteria Pseudomonas sp. in shrimp breeding water can significantly increase bacterial abundance,” the researchers reported.
Pseudomonas sp. is a probiotic bacteria commonly used to treat effluents from the fish industry through nitrification processes. Probiotic bacteria can produce antibiotic compounds and suppress the growth of pathogenic bacteria in the cultivation environment.
Consequently, Pseudomonas sp. is capable of maintaining water quality, minimizing stress, and increasing shrimp survival rates.
“The application of nitrifying bacteria Pseudomonas sp. in L. vannamei cultivation was more effective than without adding bacteria. Bacterial application at a density of 109 CFU mL-1 showed the best performance during the breeding period, as well as improvement in water quality (reduction of NH3 and control of NO3– and NO2– levels), sustaining production performance, and reducing stress in shrimp,” they concluded.
In this regard, the researchers recommend that vannamei shrimp cultivation should be conducted using the application of nitrifying bacteria with a density of 109 CFU mL-1 during appropriate time intervals.
Yuni Puji Hastuti
Department of Aquaculture, Faculty of Fisheries and Marine Science
Jl. Raya Dramaga, Bogor, 16680
West Java, Indonesia
Reference (open access)
Hastuti, Y.P., Siregar, A., Fatma, Y.S. et al. Application of a nitrifying bacterium Pseudomonas sp. HIB_D to reduce nitrogen waste in the Litopenaeus vannamei cultivation environment. Aquacult Int (2023). https://doi.org/10.1007/s10499-023-01123-6