FATEMEH SHAYESTEH - Department of Fisheries, Faculty of Marine Science and Technology, University of Hormozgan, Bandar Abbas, Iran

This study was conducted to evaluate the ethyl acetate extract from marine isolate Streptomyces sp. TSIA8, for it s in vitro inhibitory activity against pre-formed biofilm and in interference with the biofilm-forming of two biofilm-producing bacteria (E. coli UCCb1 and E. coli UCAa4). Sensitivity of Two biofilm-producing bacteria to ethyl acetate extract of Streptomyces sp. TSIA8, was investigated in planktonic and biofilm states by cell viability and crystal violet assay, respectively. It was found that bioactive compounds from Streptomyces sp. TSIA8 interferes withthe formation of biofilms and disrupts established biofilms. Ethyl acetate extract reduced biofilm formation in the isolates E. coliUCCb1 and E. coli UCAa4 with SMIC50 of 32 and 256 μg/mL, desirable SMIC50 of bacteriocin for biofilm disruption were 64 and512 μg/mL, respectively. The present findings indicated that ethyl acetate fraction of Streptomyces sp. TSIA8 has the ability to inhibitthe formation of biofilm and disrupt established biofilm

Streptomyces sp., Escherichai coli, Biofilm, marine bacteria.