Document Type : Research Paper
Authors
1
Ph.D. Student, Fisheries Department, Faculty of Natural Resources, University of Tehran, Karaj, Iran
2
Professor, Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
3
Associate Professor, Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran
Abstract
Nowadays, due to the overuse of antibacterial substances, some strains of bacteria showed a resistance to them. Hence, it is necessary to use new effective methods to control diseases caused by these strains. Yersiniosis that occur in some aquatic species, is caused by Yersinia ruckeri, a Gram-negative rod-shaped enterobacterium. In recent decade, a new approach developed to control pathogen using synthetic polymers with antibacterial properties, one of this synthetic polymer is Polyethyleneimine (PEI) that many studies reported its antimicrobial properties in aquaculture activities. Thus, the purpose of this study was to control Yersinia ruckeri by impregnating the zeolite with Polyethyleneimine and install it as an antibacterial filter in the fish tank. In this study, clinoptilolite zeolites with two concentrations were used, the first sheet(I) containing 15g of zeolite activated by 30 ml of toluene and then added it 1ml of EPO and 1ml of PEI, for the second sheet(II), the same procedure was run, but 2ml of EPO and 2ml of PEI were used, after that both sheets stirred under heat to give the desired agent and then transferred to the zeolite to produce the substrates treatments as two kinds of filters. Then ability of two anti-bacterial substrates tested to remove Yersinia ruckeri in the presence of the minimum bactericidal concentration (MBC). The growth inhibition zone also tested at concentrations of 1.8×108 to 1.8×101 CFU/ml-1 and 1.8×104 CFU/ml-1. The results showed that zeolite coated with two concentrations of PEI polymer have the potential to remove Yersinia ruckeri at 1.8×103 to 1.8× 101 CFU/ ml-1. The bacterial concentration decreased by 54% and 70% at the bacterial concentration of 1.8×103 CFU/ml-1 for zeolite coated with concentrations of I and II, respectively. Also, the growth zone diameter positively correlated with zeolite weight, the growth zone diameter for 0.05g zeolite by concentration I and II were 10.7,11.3 mm, and for 0.1 g were 15.23, 15.88 mm and for 0.15g were 18.75, 19.11 mm respectively. Finally, it was concluded that the PEI polymer-impregnated zeolite, as an antibacterial substrate, exhibits its best appliance at the bacterial concentration of 1.8× 103 CFU/ ml-1.
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