Vibrio sp. MM5 inhibitions by dissolved oxygen and pH in the culture system of Gracilariopsis lemaneiformis

The red macroalga Gracilariopsis lemaneiformis show great potential in controlling bacterial infections in aquaculture by elevating elevating dissolved oxygen (DO) and pH levels. In this study, we investigated the inhibitory mechanism of G. lemaneiformis on Vibrio sp. MM5, a prevalent aquatic pathogen, under four conditions: high DO (17.59 mg/L, group O), high pH (9.94, group P), combined high DO and high pH (group PO), and co-culture with G. lemaneiformis (group GL). All treatments significantly reduced bacterial abundance, motility (swimming and twitching), and biofilm formation, with the strongest inhibition effects observed under combined stress and co-culture. Integrated transcriptomic and metabolomic analysis revealed that the oxidative stress and energy metabolism disruption were central to the observed inhibition.