Application of Bacteriophages to Treat Toxic Gas-producing Bacteria Desulfovibrio spp. in Shrimp Ponds

Abstract

Desulfovibrio spp. bacteria pose significant challenges in shrimp aquaculture by producing hydrogen sulfide (H2S), which depletes oxygen levels and hinders shrimp growth. The increasing prevalence of antibiotic-resistant bacteria necessitates the exploration of alternative control methods. This study investigates the potential of bacteriophages as a biological solution to inhibit Desulfovibrio spp. in shrimp ponds. Six bacteriophage strains (ST231, ST22, φMix 1, φS8, φS9, and φMix 2) were evaluated using plaque assays at three time points (3, 6, and 18 hours). Results demonstrated that most bacteriophages significantly reduced bacterial density over time, with ST22 showing the most substantial inhibition (p<0.05). Genomic analysis of bacteriophage ST22, published in the GenBank database, revealed genes related to Desulfovibrio spp., specifically Deltaproteobacteria and Desulfobacteraceae. The study also found that bacteriophage treatment led to decreased H2S and NH3 levels and increased dissolved oxygen in simulated pond environments. Morphological changes in bacterial colonies post-treatment further supported the phages’ inhibitory effects. These findings suggest that bacteriophage ST22 is a promising biological alternative to antibiotics for preventing and controlling diseases caused by Desulfovibrio vulgaris in shrimp aquaculture, though further research is needed to assess long-term ecological impacts and efficacy in complex pond ecosystems.