Insight into the bacterial communities in the sediment–water interface across different salinities of Pacific White shrimp, <i>Penaeus vannamei</i>, by metabarcoding

Microbes play an important role in the food chain by metabolizing organic matter, cycling nutrients, and maintaining a dynamic equilibrium among organisms in water and sediment. The objective is to study the fluctuating taxonomic microbial diversity profile in the sediment-water interface at different days of culture (DOC) of Penaeus vannamei in varying salinities using the Illumina MiSeq platform. Sediment samples were collected in Tamil Nadu, India, from low-saline, brackish water, and high-saline ponds at 30, 60, and 90 DOC. Bacterial richness and diversity in species were high in low-saline ponds. Beta-diversity variation indicated more differences in bacterial composition in high- and low-saline ponds. The predominant phyla observed were Proteobacteria, Actinobacteria, Chloroflexi, Bacteroidetes, Firmicutes, and Cyanobacteria. High-saline ponds accounted for more nitrification bacterial communities, sulfur-reducing bacterial communities, sulfur-oxidizing bacterial communities, and high redox potential, whereas denitrification bacterial communities were high in brackish water ponds.