401ANTIBACTERIAL ACTIVITY OF TAMARINDUS INDICA SEEDS EXTRACT AND STUDY THE EFFECT OF EXTRACT ON ADHERENCE AND BIOFILM PRODUCTION OF SOME BACTERIAThe present study was investigate the antibacterial activities of Tamarindus indica alcoholic seeds extract and study the effect of extracts on adherence and biofilm production of some bacteria (E coli pseudomonas aerugnosia, Enteriococcus, Sallmonella typhi, Shigella dysentery, Staphylococcus auerus, Bacillus suitlus) also phytochemical screening of the extract has been studied. The antimicrobial activities of alcoholic seed extract were determined by agar diffusion method. The ability of adherence was determine by using plastic and glass tubes also biofilm production was determined by using microliter plate .the results indicates that the seed extract of Tamarindus indica showed marketable antimicrobial activity against all bacterial isolates especially at concentration 200µg/ml . E coli and Sallmonella typhi were more susceptible to seed extract when compare with other bacterial isolates with inhibition zone 35mm. The phytochemical analysis revealed the presence of alkaloid, flavonoid, saponins, glycosides, terpenoids while tannins absence in seed extract. The results indicate that all bacterial isolates have ability to adhere to smooth surface (plastic and glass tubes) but in different degree. The ability to adhere of all bacterial isolates were shown to be significantly higher in glass surface (glass tubes) than in polystyrene surface (plastic tubes) pseudomonas aerugnosia E coli, Enteriococcus and Sallmonella typhi showed high adherent growth than other bacterial isolates. Also, it was found that seed extract (100 µg/ml, 200 µg/ml) decrease the adherent growth of tested bacteria. The results showed that all tested bacteria have ability to form biofilm with different thickness degree the absorbance value range (1.7-0.8). Sallmonella typhi, pseudomonas aerugnosia Enteriococcuss how high biofilm production with absorbance values (1.7,1.25,1.08) respectively. Also it was found that Tamarindus indica seeds extract inhibit bacterial adhesion to microtiter plate surface and consequently decrease the absorbance value of biofilmsh_frbio@yahoo.comResearch512014Tamarindus indica,Antibacterial,Phytochemical screening,Adherence,BiofilmShaymaa fouad RasheedDepartment of Biology, College of science, University of Baghdad, Al Jadiria, Baghdad, Iraq.