SUMMARY
Tannase has different benefits in food, chemical and pharmaceutical fields. Seventeen Serratia marcescens isolates were collected from septicemia, wound infections and hospital environment(babies incubators).These isolates were identified by biochemical tests and Vitek 2 system that contained Vitek GNI card then conformed by16S rRNA gene products(amplified size 179 bp) for genotypic detection. After that, they screened for higher tannase production and Serratia marcescens b9 was a better producer of tannase with a larger diameter of a dark green zone. The tannase activity was increased to 63U/ml when this isolate was cultivated under the optimal conditions which consisted of using nutrient broth supplemented with ber leaves at pH value 5.5 and a temperature equals to 37°C for 72 hours. In the partial purification of tannase, ammonium sulfate was more efficient than organic solvents, since it was found that 70% saturation of ammonium sulfate led to precipitate of tannase with tannase activity of 80U/ml. In contrast, 30% of ethanol, acetone, and isopropanol led to precipitate of tannase with different levels of activity ranged between 45-47U/ml. Consequently, ber leaves have a potential as an effective and much cheaper (economical) substrate for tannase production in comparison with traditionally used substrates like tannic acid.