Effects of different disinfectants on water quality and microbial community structure of Litopenaeus vannamei

We analyzed the total number of heterotrophic bacteria and Vibrio, ammonia and nitrite nitrogen of water, survival rate of larvae, bacterial community of larvae and rearing water of Litopenaeus vannamei after different disinfection treatment of hatchery water, including iodine (I₂), chlorine dioxide solution (ClO₂), formaldehyde (HCHO) and bleach Ca(ClO)₂. The results show that the total number of bacteria and Vibrio in the formaldehyde group was lower, and the number of Vibrio was the lowest. The concentration of ammonia and nitrite nitrogen in the four disinfectants groups was lower than that in the control group, and the concentration of bleach group was the lowest. The survival rate of the larvae in the formaldehyde group was significantly higher than those in the other four groups (P<0.05). The 16S rDNA high-throughput sequencing reveals that the disinfectant changed the microbial community and abundance of dominant bacteria of the hatchery water and the larvae. The bacterial composition of the hatchery water was more complex than that of the larvae, and the early stage was more complex than the late stage. Besides, the genera OM43_clade, Alcanivorax, Erythrobacter, Altererythrobacter, Tenacibaculum, Enhydrobacter and Gilvibacter were enriched in the N₆−Z₁ periods of rearing water; Donghicola, Cohaesibacter, Phaeodactylibacter, Candidatus-Cquiluna and Ruegeria were enriched in the M₁−P₁ periods of rearing water, while Vibrio, Planomicrobium, Exiguobacterium, Psychrobacter, Acinetobacter, Bacillus, Methylophaga and Halomonas had high abundance in the larvae.