Tarbiat Modares University Pathobiology Research 2538-3000 22 4 2019 10 01 Isolation and Identification of Halophilic Bacteria Producing Asparaginase Enzyme from Urmia Lake جداسازی و شناسایی باکتری‌های نمک‌دوست تولیدکننده آنزیم آسپاراژیناز از دریاچه ارومیه 197 202 19360 EN P. Moghadam Department of Microbiology, Faculty of Science, Urmia Branch, Islamic Azad University, Urmia, Iran F. Khadivi Derakhshan Department of Biology, Faculty of Science, Urmia Branch, Islamic Azad University, Urmia, Iran Journal Article <strong>Aims:</strong> The present study was aimed to investigate isolation and identification of halophil bacteria producing asparaginase from Urmia Lake and the effect of different salt concentrations and temperature on asparaginase production.<br> <strong>Materials & Methods:</strong> The water and mud samples from Urmia Lake were cultivated in MH and SWN media for isolation of halotolerant bacteria. Then, the asparaginase production rate was investigated in saline M9. The asparaginase production rate by isolates was investigated in different salt concentrations (10, 20, 30, and 40%) and temperatures (30, 35, 37, 45, and 50°C). Two isolates with a high production rate of asparaginase were stained by gram stain method and were identified by <em>16S rRNA</em> sequencing.<br> <strong>Findings:</strong> In the present study, 57 isolates were obtained which 10 isolates showed asparaginase production. Among these, 2 isolates (A₂ and A₃) were selected as superior isolates. The isolate A₃ has shown the largest halo (54mm) at 35°C and 10% salt concentration. Moreover, the isolate A₂ has shown the largest halo (56mm) at 35°C and 40% salt concentration. The <em>16SrRNA</em> sequencing showed that the A₂ isolate was similar 98.9% to the <em>Halomonas elongata</em> strain, and the A₃ isolate was similar 100% to the <em>Bacillus aryabhattai </em>strain.<br> <strong>Conclusion:</strong> The bacteria isolated from Urmia Lake are potential source of asparaginase enzyme. <em>H. elongate </em>and <em>B. aryabhattai </em>strains isolated from Urmia Lake can be used to production of asparaginase without side effects for cancer patients.<strong><span dir="RTL"></span></strong> <strong><span dir="RTL"></span></strong> https://mjms.modares.ac.ir/article_19360_42a35b21c91691fb5cd8724fa1a105ec.pdf