fatemeh salar Hosseini - Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
Navid ramezanian - Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran
zoheir shokouh saljoghi - Department of Fisheries, Faculty of Natural Resources, Isfahan University of Technology, Isfahan, Iran

In recent years, designing of environmentally friendly and high performance materials based on biodegradable polymeric systems have much interest in scientific researches. The benefit of using biodegradable polymers is their potential of decomposing naturally over short periods of time in nature [1]. Nowadays, attention is great to Chitosan due to the wide range of applications, especially in the aquaculture hatcheries systems, because of its ease of moulding into gel, sponge, nanocomposite, scaffolds, powder, beads, and films [2].The antibacterial activity of the composites were evaluated against Streptococcus iniae and the diameter of the zone inhibition of bacteria for the composite containing CS (4 g), BN (2 g) and ZnO (20 mg), was 20.2 mm, the composite containing CS (4 g), BN (4 g) and ZnO (20 mg), was 11.54 mm, the composite containing CS (4 g), BN (2 g) and ZnO (60 mg), was 11.62 mm, and the composite containing CS (4 g), BN (4 g) and ZnO (60 mg) had no antimicrobial properties (fig. 1). The antibacterial activity of these composites provides the possibility of further clinical investigations leading to its application in aquaculture industry.

antibacterial properties, chitosan, bentonite, ZnO nanoparticles