<![CDATA[Acetone and hexane extracts of cyanobacteria Westiellopsis prolifica was tested In vitro. Antibiofilm activity was evaluated by biofilm production assay against six pathogenic bacteria in which three are Gram- positive bacteria "Staphylococcus aureus , B.subtilis, and Streptococcus sp. " and three are Gram- negative bacteria" Shigella sp., Proteus sp. and Pseudomonas aeruginosa " in additions two isolates of fungi "Aspergills niger and Candida albicans".The results showed that crude acetone extract for W .prolifica better than hexane extract ,and more efficient on negative gram bacteria than positive gram bacteria. The highest biofilm inhibition of acetone extract against Shigella sp. reached to (10 ) %, while lower biofilm inhibition ( 68)% against A. niger compared to hexane, with the highest biofilm inhibitory rate in C.albicans (42 )% and lower biofilm inhibition against Proteus sp. reached to ( 98 )%.at concentration 100 µl. As well as Congo red agar method showed that acetone extract for W .prolifica better than hexane extract in the anti-biofilm formation at 50 µl, The best anti-biofilm activity of acetone extract against B. subtilis , Shigella sp., Proteus sp. and C. albicans (++ )While A. niger (+) showed slight effectiveness .On the other hand the hexane extract showed little efficacy against biofilm for all studied isolates .Key words: Westiellopsis prolifica, Active compounds, Antibiofilm, Partial purification, GC/MS Analysis.]]>
