Evaluation of Antibacterial Characteristics of Hemolymph of Cerastoderma and Didacna Bivalves in the southern Coasts of Caspian Sea

The aim of this study was to evaluate the antibacterial properties of the hemolymph of two bivalves of Cerastoderma and Didacna in the southern coast of the Caspian Sea. In this initial study to determine the antimicrobial activity disc diffusion method, then MIC and MBC were used. In this study, different concentrations of 25, 12.5, 6.25, 3.125, 1.56 percent was used. The highest and the lowest diameter of inhibitory zone in different concentrations against (ATC C25922) Escherichia coliin Cerastoderma was observed for concentration of 25% and 1.56%, and in Didacna for concentration of 25% and 3.125%. Also, the highest and the lowest diameter of inhibitory zone against Klebsiella pnuemoniae (NCTC5056) in hemolymph two bivalve Cerastoderma was observed for concentration of 25% and 3.25% respectively, and in Didacna for concentration of 25% and 3.125%. The highest and the lowest diameter of inhibitory zone against Entroccus faccium in Cerastoderma was observed for concentration of 25% and 3.25%, and in Didacna for concentration of 25% and 1.56%. With increasing the concentration of hemolymph, its antibacterial activity increased significantly (p<0.05). Didacna had a lower MIC compared to Cerastoderma against E. coli and P. Klebsiella, but the MIC of hemolymph of Cerastoderma was significantly (p<0.05) lower than Didacna against E. Facium.Thus, according to our findings Cerastoderma and Didacna can be considered as the important source of valuable bioactive compounds which can be used for producing antimicrobial drugs.