IDENTIFICATION OF MARINE IRON REDUCING BACTERIA (IRB) ISOLATED FROM PASIR PANJANG, PORT DICKSON, NEGERI SEMBILAN AND ITS ANTIMICROBIAL ACTIVITIES

Abstract

This study focused on the identification of iron reducing bacteria (IRB) isolated from the waters off Port Dickson, Negeri Sembilan and its antimicrobial activity. Ten marine IRB isolates were successfully obtained from five different steel sample coupons immersed in seawater off Pasir Panjang, Port Dickson, Negeri Sembilan for one month. The samples were cultured in VMNI medium for 72 hours at 37 ^oC.  A total of 10 pure colonies named A1, C1, etc. were obtained. Identification of the isolates was done using Gram-stain and polymerase chain reaction (PCR). Then, the antimicrobial activity of IRB isolates was investigated using the overlay method against four pathogens, namely Escherichia coli, Enterococcus faecalis, Salmonella enterica serovar Typhi and methicillin-resistant Staphylococcus aureus (MRSA). These four pathogens were selected because of their predominance in causing disease in humans and animals. The antimicrobial activity results  showed inhibition zones except for isolates A1 towards E. coli and C1(2)(2) towards S. Typhi. Eight out of ten isolates of IRB strains showed antimicrobial activity towards selected pathogens. This study was able to demonstrate that there is antimicrobial activity of IRB against selected pathogens and, in the meantime, manage to identify the IRB down to the species level as well. This finding showed potential uses of IRB against pathogens that warranted further research.