ANTIMICROBIAL PEPTIDE FROM HEMOCYTE OF GREEN MUSSEL (Perna viridis) AGAINST Vibrio alginolyticus AND Streptococcus iniae

Abstract

The emergence of new diseases and increasing resistance of pathogenic bacteria to conventional antibiotics are significant problems in aquaculture worldwide. Antimicrobial peptide from marine bivalve offers an alternative to prevent spreading of bacterial pathogenic in aquaculture. Antimicrobial peptides are important components of the host immune response against microbial invasion. The present study was to investigate the potential of antimicrobial peptide from hemocyte of Perna viridis. Three organic solvents based on different polarity namely methanol, acetone and chloroform were used to prepare the hemocyte extraction. Antimicrobial assay was conducted with disc diffusion method and measurement of minimum inhibitory concentration (MIC) value against two pathogenic bacteria in aquaculture, Vibrio alginolyticus and Streptococcus iniae. The result indicated that antimicrobial activity from hemocyte of P. viridis dependent on solvents extraction and type of bacterial target. All of the test fractions were not perform inhibitory activity against V. alginolyticus, but showed inhibitory activity to S. iniae. The acetone fraction showed highest diameter inhibitory zone (24 mm) as compared to methanol (16 mm) and chloroform extract (11 mm). Statistically, diameter of inhibitory zone for methanol, acetone, and chloroform fractions are significant different (P<0,05). MIC value of methanol, acetone and chloroform fraction were 50-100 µg/ml, 6,25-12,5 µg/ml and 50-100 µg/ml respectively. All treatments qualitatively showed strength response to S. iniae. Acetone fraction showed highest inhibitory zone was purified with Thin Layer Chromatography and subjected to SDS-PAGE to estimate the molecular weight of protein present. After electrophoresis process, two clear band were detected in the gel which represented proteins of molecular weight 9,4 kDa and 5,4 kDa. The findings of the present study confirmed that antimicrobial peptide from hemocyte of P. viridis has a potential sources as new therapycal agent in aquaculture. Keywords: antimicrobial peptide, hemocyte, Perna viridis