Evaluation of the of the extract of seeds Citrus paradisi for inhibition of Vibrio parahaemolyticus in Litopenaeus vannamei

Abstract

This quantitative research study assessed the potential of Citrus paradisi seed extract to inhibit the proliferation of Vibrio parahaemolyticus and improve the survival of Litopenaeus vannamei in vitro. Farming of white shrimp L. vannamei has high mortality rates because of the presence of the pathogenic V. parahaemolyticus, which is treated with antibiotics, and this produces selection pressure and antibiotic resistance. Accordingly, this research was carried out in the microbiology laboratory at Pontificia Universidad Católica del Ecuador, Manabí from October through December 2019. There were conducted some assays of minimum inhibitory concentration –MIC– Test, motility, growth, biofilm, and toxicity with L. vannamei postlarvae. The findings reveal that there is inhibition of bacterial growth in the assays at different concentrations; the activity in MIC is seen in 43 mg/ml of extract, and in the motility assay the inhibition corresponds to 2,6 mg/ml. In bacterial growth assays, concentrations of 5,3 mg/ml cause inhibition, whereas in biofilms inhibition occurs at 2,6 mg/ml. By working to improve survival of larvae, toxicity testing show that when they are subjected to concentrations ranging from 0,08 to 0,325 mg/ml, they have larval survival up to 60%, but with concentrations of 0,650 mg/ml, larval survival decreases by 33%; this determines that higher concentrations are more toxic for postlarvae. It is concluded that high concentrations of C. paradisi seed extract do inhibit bacterial proliferation of V. parahaemolyticus, and it is recommended as a disinfectant in facilities of L. vannamei larval farming.