In this study, the antibiofilm and antioxidant activities of the crustose coralline alga (CCA)
Lithophyllum sp. collected from the central Red sea was investigated. The dried CCA samples were extracted
with hot water and methanol. Both extracts were tested against marine biofilm forming bacteria to assess the
antibiofilm activity. Results showed that methanol extract of the CCA inhibited bacterial growth
considerably. The water extract revealed higher antioxidant activity than the methanol extract. The FT-IR
spectrum of the CCA showed the presence of functional groups like alkanes, alcohol, carboxylic acid, ethers
and esters. In general, results of the present study indicated that CCA produces bioactive compounds, which
can inhibit the attachment of unwanted marine bacteria on their surfaces.