A total of 12 gut isolates were isolated from healthy adult shrimp Penaeus monodon. Consecutive screening
approaches were done to evaluate the anti-vibrio and anti-quorum sensing potential towards Vibrio harveyi
VSH5 and Chromobacterium violaceum MTCC2656. Among the 12 isolates, the probionts Bacillus sp.
AVP03 & AVP07 rendered maximum activities in both in-vitro and in-vivo tests. The study also suggests
that the isolated anti-vibrio probionts possessed anti-QS (quorum quenching) activity which significantly
reduced the mortality when compared to the animals treated with the pathogen in post larvae and juvenile
challenge study. Both probionts were reached their stationary phase within 6 hrs in tryptic soy broth (TSB)
and hence it was considered as best medium for their mass culturing. Studies regarding haemolytic activity
of the isolated probionts revealed that non-toxic in nature and safety for use. Thus they can be effectively
used as probiotics in aquaculture either separately or in combination.