Isolation and Identification of Biofilm Bacteria from Microfouling Assemblage Developed on Artificial Materials Submerged in the Red Sea

Abstract

Biofilm bacteria are primary surface colonizers in marine biofouling assemblage on submerged surfaces and dominate the early microfouling phase. They are an important target in the design of antifouling treatment due to their ability to initiate biofouling and support of the subsequent macrofouling colonization. In this study, several biofilm bacteria were isolated from Petri dish and polyvinyl chloride (PVC) pipes submerged in the Red Sea coast for a week. The biofilm-forming bacteria were isolated by spread plate method under standard conditions and identified by 16S rRNA sequencing method. Each of the isolates was evaluated for biofilm formation qualitatively using the tube assay. Microtiter plate assay was used to quantify the biofilm produced by the selected organisms. A total of 11 out of 21 isolated bacteria were able to form biofilm under laboratory conditions. Most of the isolates (7 out of 11) are from the genus Pseudoalteromonas and one isolate each from the genera Halomonas, Marinomonas, Psychrobacter and Vibrio. This study indicated that the bacterial community forming the biofilms on hard substrates in the Red Sea are diverse and capable of forming biofilms on surfaces under laboratory conditions. These isolates could be used as target microorganisms for antifouling screening assays.