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

Abstract

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 14.67x103 to 22.67x103 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.