Antimicrobial of nyirih (Xylocarpus granatum) against pathogens of tiger shrimp post-larvae

Background: Xylocarpus granatum has been used as a medicinal plant by coastal communities, which may indicate that this plant is a potential source of pharmaceuticals. Methods: Xylocarpus granatum leaf extract was tested as an antimicrobial agent for pathogens infecting tiger shrimp post-larvae. Of the treatments applied to the post-larvae, 25 were crudely extracted with ethanol, distilled water, and seawater solvent given by immersion. Vibrio harveyi and Saprolegnia sp. were microbial species used for the test. Results: X. granatum extract had the potential to inhibit V. harveyi and Saprolegnia sp., reducing infection and improving the survival of shrimp. Shrimp soaked with X. granatum extract had a total Vibrio count ranging from 14.67x10 3 to 22.67x10 3 CFU/ml. The survival rate of shrimp was recorded as 53.33% to 78.67% and 54.67% to 76.00% due to V. harveyi , and Saprolegnia sp infection, respectively. The relative percentage of the survival of shrimp protected from V. harveyi and Saprolegnia sp infection in treatments compared to negative controls ranged from 40.61% to 72.89% and 35.84% to 66.12%, respectively. Conclusions: Leaf extracts of X. granatum , which might have better antimicrobial activities to prevent tiger shrimp from pathogenetic infection, were consecutively extracted ethanol at 800-1,000 ppm, distilled water at 800-1,000 ppm, and seawater at 1,000 ppm.