Screening Native L-glutaminase Producing Bacteria and Enzyme Production by Submerged Fermentation

L-glutaminase is widely used in pharmaceutical and food industries, such as treatment of leukemia. This study aimed to isolate and identify native L-glutaminase producing bacteria in Iran and to study its quantitative activity in submerged fermentation. The L-glutaminase producer bacteria were isolated from soil and water samples of Zayandehrod and Karoon Rivers and also from the sediments of fishing pools. The isolates were screened using minimal glutamine agar (MGA) medium for producing L-glutaminase enzyme. The samples were grown in a submerged fermentation system using mineral salt glutamine (MSG) medium, and the produced enzyme was assayed quantitatively. The best glutaminase producer bacterium was identified by the gram-staining and biochemical tests. In this study, 11 glutaminase producer strains were isolated. Bacillus subtilis CH3-GLU strain showed maximum enzyme productivity 37.91±0.62 U/ml at temperature 45° C after 96 hours. Based on this study, Bacillus subtilis CH3-GLU showed the highest rate of glutaminase production.