Recently, Guangxi Academy of Marine Sciences published a research paper entitled “Microorganism-mediated denitrogenation of aquaculture systems provoked by poly-β-hydroxybutyrate (PHB)” in Nature's journal NPJ clean water (JCR1; IF2023=10.4) online. The research paper entitled “Microorganism-mediated denitrogenation of aquaculture systems provoked by poly-β-hydroxybutyrate (PHB)” was published online by Guangxi Academy of Marine Sciences, with researcher Yu Ermeng as the corresponding author. The paper was supported by the National Key Research and Development Program of China (2023YFD2400504).

PHB (poly(β-monohydroxybutyrate)) is a new type of biomaterial with the property of complete biodegradation in nature, and it is one of the most carbon-neutral biobased materials, which can be used as a solid substrate for biofilm formation and as a slow-release carbon source to promote microbial growth. In this study, PHB was applied to the water treatment unit of a zero water exchange aquaculture system for largemouth bass, and its application parameters were optimized by analyzing the water treatment performance, which resulted in a removal rate of about 90% of NO3-N, NO2-N, and TN in the water column. We further utilized 16s rRNA high-throughput sequencing and Geochip technology to excavate the mechanism of its efficient nitrogen removal, and found that the significant enrichment of PHB as a slow-release carbon source for nitrogen-removing microorganisms (Cetobacterium, Polynucleobacter, Lacibacter) in the culture system as well as the enhancement of denitrifying nitrogen-removing functional genes (nirK, nirS , narG) were the main reasons for the high nitrogen removal capacity of PHB. Finally, combined with the health evaluation of farm animals, we provide basic data for the application of PHB in the tailwater treatment of largemouth bass, which has a broad application prospect in the field of biofilm treatment of farm tailwater.

Link to related article: https://doi.org/10.1038/s41545-024-00339-0