Effect of mangrove plant (Sesuvium portulacastrum) extract against Vibrio harveyi during shrimp larviculture

Abstract

Aim: The present study aimed at finding a potential antagonistic activity of the leaves of mangrove plant Sesuvium portulacastrum against pathogenic Vibrio harveyi during shrimp larviculture. Methodology: Crude extract obtained from the leaves of mangrove plant S. portulacastrum was screened for its antagonistic activity against V harveyi and the minimum inhibitory concentration was determined. Crude extract was characterized for its phytochemical composition by GC-MS and FTIR analysis. The antagonistic activity of S. portulacastrum crude extract was tested against V harveyi during Penaeus monodon larviculture. Results: MIC of S. portulacastrum extract was 100 ug against 1 × 103 CFUml-1 of V harveyi. When V harveyi was cultured in Luria Bertani broth with crude extract of S. portulacastrum (100 μg ml-1) the growth and its virulence factors became weak. The cumulative percentage on mortality of postlarvae was 54% in 30 days, whereas control tank showed 67% mortality. Differences in reduction on the cumulative percentage mortality in the treatment tank was 13% as compared to control. Using statistical analysis, significant differences (P < 0.05) were observed between control and treatment. Interpretation: This study endorse that crude extract of S. portulacastrum can be used as non-antibiotic and bio-therapeutic proxy to control bio-luminescence disease causing V harveyi in the shrimp larviculture practice.