Not AvailableExperiments were conducted to explore the colonization of beneficial bacteria in shrimp
Penaeus vannamei grown in different sources of biofloc and clear water. Beneficial effect in
terms of extracellular enzyme production and antibiofilm activity of the isolated strains was
determined. Heterotrophic bacterial population were isolated by using different agar plates and
resulted in isolation of 94 isolates in total. Extracellular enzyme production such as amylase,
protease, lipase, cellulase, xylanase, and pectinase were screened. Antibiofilm activity of
culture supernatants of enzymatic strains against pathogenic Vibrio was also determined. Out
of 94 strains screened, 36 strains were found to produce amylase enzyme, 20 strains protease,
27 strains lipase, 6 strains cellulase, and 8 strains xylanase. Totally, 21 isolates selected for
further identification and different species of Cobetia, Exiguobacterium, Bacillus,
Marinilactibacillus, Staphyllococcus, and Novosphingobium genera from biofloc treatments
were identified. In control group animals, strains of Bacillus and Exiguobacterium
were isolated and identified. The genus Exiguobacterium was found common in all the
different treatments and control. The result showed that shrimp grown on biofloc system
allows colonizing more beneficial bacteria in gut than control. Few promising strains under
Bacillus genus were found to produce all the extracellular enzymes along with antibiofilm
activity.Not Availabl
