Temporal changes in microbial community structure in the culture water of white leg shrimp (Penaeus vannamei) treated with ozone nanobubbles

Abstract

Microbial communities plays a crucial role in maintaining water quality and the health of aquatic animals. This study examined investigated temporal changes in microbial community structure in the rearing water of Penaeus vannamei cultured in an intensive indoor system under the influence of ozone nanobubble (NB-O₃) treatment, using 16S rRNA next-generation sequencing. The experiment was conducted on 84 days with two treatments. Water samples were collected on days 1, 60, and 84 of the culture periods for microbial community analysis. At the phylum level, Proteobacteria, Bacteroidota, and Actinobacteriota dominated throughout the culture period, with average relative abundances of 66.8, 18.8, and 9.9% in the NB-O₃ treatment, compared with 59.0, 19.4, and 16.1% in the control. Over time, the relative abundance of Proteobacteria in the NB-O₃-treated tanks gradually decreased from 80.0% (day 1) to 54.6% (day 84), while Actinobacteriota increased from 2.5% (day 1) to 18.7% (day 84). The genus Marivita showed a sharp decline from 8.38% (day 1) to 0.43% (day 84), whereas beneficial genera such as Mycobacterium, Ruegeria, and Paracoccus increased in the NB-O₃ treatment. These findings suggest that NB-O₃ treatment promotes a beneficial and more stable microbial community in shrimp culture water.