Molecular Docking Study of Bio-Inhibitors Extracted From Marine Macro Alga Ulva Fasciata Against Hemolysin Protein of luminescence Disease Causing Vibrio Harveyi

Shrimp grow-out and hatchery systems are being affected by bacterial disease particularly Vibrios. The use of chemotherapeutic agents in aquaculture practices has to lead to the development of resistance among aquatic bacteria. Thus, health management becomes of major importance in aquaculture. Under this situation, progressing bio-inhibitors from marine resources are most appropriate to be considered against pathogenic bacteria. Molecular docking is an appropriate tool in structural biology and computer-assisted drug design to predict and neutralize a target protein of known diseases. In this study, marine macroalga Ulva fasciata was aimed at developing inhibitors against luminescence disease-causing pathogenic bacteria Vibrio harveyi. U. fasciata was collected from the intertidal zone of Thoothukudi, Tamil Nadu, India. Extract of U. fasciata was tested against growth and virulence factors of V. harveyi during Penaeus monodon larviculture. For molecular docking, the homology modeling of virulence of hemolysin protein of V. harveyi was designed and used for docking studies against the compounds of U. fasciata as identified by GC-MS analysis. Extract of U. fasciata@200 mg mL-1 had exhibited reductions on Cumulative Percentage of Mortality (32.40%) in postlarvae against the challenge of V. harveyi infection. In docking analysis, the bio-inhibitor Methyl dehydroabietate showed the highest binding affinity among compounds docked. Statistical analysis had revealed significant differences (p<0.05) in trials. Therefore, it was proved that the bio-inhibitors from U. fasciata will be a better option for controlling luminescence disease-causing V. harveyi in shrimp grow-out practices.