Effects of potassium monopersulfate on nitrification activity and bacterial community structure of sponge biocarrier biofilm in Litopenaeus vannamei aquaculture system

ABSTRACT

Effects of potassium monopersulfate (KMPS) on the nitrification activity, aquacultural water quality and bacterial community structure of sponge biocarriers with pre-cultured biofilm (SBBF) were analysed through shaking flask experiments and L. vannamei aquaculture experiments. Changes in the ammonia oxidation rate (AOR) and nitrite oxidation rate (NOR) of SBBF under six KMPS concentration treatments (0, 1, 2, 3, 4 and 5 mg/L) were studied. The results showed that the AOR and NOR of SBBF treated with high concentrations of KMPS (3, 4 and 5 mg/L) were significantly lower than those of the control group (CK) (p < 0.05). However, compared with the first dosing of NH₄Cl and NaNO₂, the inhibition of AOR and NOR by KMPS on AOR and NOR was weakened after the second and third dosing times. That is, AOR and NOR can recover partially or completely over time. The L. vannamei aquaculture experiment was performed using four concentrations of KMPS (0, 2, 4 and 8 mg/L). The results showed that with increasing KMPS dosage, the average and peak concentrations of NH₄⁺-N and NO₂^–-N in each treatment significantly increased (P < 0.05), and the final body weight of shrimp significantly decreased (P < 0.05). Furthermore the highest dose (8.0 mg/L) of KMPS reduced the survival rate by 9.33% compared to the CK. High-throughput sequencing analysis of the biofilm structure showed that the relative abundances of Nitrospirota, Nitrosomonas and Nitrococcus, which are related to nitrogen cycling, and beneficial bacteria including Firmicutes and Bacilli decreased with the addition of KMPS (p < 0.05).

GRAPHICAL ABSTRACT

KEYWORDS:

• KMPS
• biofilm
• nitrification activity
• bacterial community structure
• Litopenaeus vannamei

Acknowledgements

We also thank the reviewers for their remarks and suggestions. All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Yazhi Luan, Yang Wang, Ailing Xu and Zhiwen Song. The first draft of the manuscript was written by Yazhi Luan, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The datasets analysed during the current study are available in the NCBI GenBank repository. P0_0 (SAMN34258653), T0_15 (SAMN34258654), T0_30 (SAMN34258655), T1_15 (SAMN34258656), T1_30 (SAMN34258657), T2_15 (SAMN34258658) T2_30 (SAMN34258659), T3_15 (SAMN34258660), T3_30 (SAMN34258661). https://www.ncbi.nlm.nih.gov/sra/PRJNA957684. The authors confirm that the data supporting the findings of this study are available within the article. The data supporting the findings of this study are available within the article and attachment.

Additional information

Funding

This work was supported by the Key R&D projects of Shandong Province [2018GSF117022].