Identification and characterization of iron reducing bacteria attached on stainless steel immersed in Port Dickson seawater

Aims: The study focused on the isolation, identification and characterization of iron reducing bacteria (IRB) attached on stainless steel immersed in seawater. Methodology and results: Ten marine bacteria were successfully isolated from 5 different stainless steel samples immersed in seawater of Port Dickson, Negeri Sembilan. These bacteria were cultured in VMNI medium for 72 h at 37 °C and pure colonies of 10 isolates were obtained and later were used for molecular analysis. The biofilm of each strains were observed by using microscope Scanning Electron Microscope (SEM) with magnification of 3000x and 5000x and most of these bacterial cells are in a form of bacillus, coccobacillus, coccus and dicoccus. By using polymerase chain reaction (PCR), genome from 10 strains were used to amplify the 16S rRNA gene sequence and aligned using the multiple alignments software, Mega 4 Software. The phylogenetic analysis which based on the 16S rRNA sequences revealed that 6 out of 10 strains were belong to the Shewanella gfenus while the other two strains were put under the family of Alteromonodaceae and Rhodobacteraceae and one strain was not determined yet because of no accurate data from GenBank and was known as unidentified organism. Conclusion, significance and impact study: Six out of ten strains isolated are belong to Shewanella genus which was one of iron-reducing bacteria group and by using SEM, biofilm formation and bacterial cells can be observed. IRB’s role in biocorrosion are important for several sectors such as oil and gas and shipping industry and therefore, this study was undertaken to isolate, identify and perform initial characterization on IRB.