Purification and characterization of extracellular glutaminase from Aspergillus oryzae NRRL 32567

详细信息    查看全文

• 作者：Wael Bazaraa ; ^{waelbazaraa@hotmail.com" class="auth_mail" title="E-mail the corresponding author} ; Ahmed Alian ^{hebabiotech@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Nagwa El-Shimi¹ ; ^{shahinaz29@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; Reda Mohamed ^{reda_karrim@yahoo.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Aspergillus oryzae ; Characterization ; Flavor enhancer ; L-glutaminase ; Purification ; Salt tolerant
• 刊名：Biocatalysis and Agricultural Biotechnology
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：6
• 期：Complete
• 页码：76-81
• 全文大小：652 K

文摘

The glutaminase produced from Aspergillus oryzae NRRL 32567 was purified (10.2 folds) using ammonium sulfate fractionation followed by gel filtration on Sephadex G-75. SDS-PAGE of the purified glutaminase showed the presence of one band with a molecular weight of 68 kDa. Optimum pH was 7.0 while a temperature range 30–40 °C was optimal the activity. The highest pH stability was obtained at pH 7.0 while a temperature range 30–40 °C resulted in the highest temperature stability. The apparent K_m value was calculated from the Linenweaver-Burk plot and was found to be 4.5 mM. Glutamine was the preferred substrate for the enzyme and the maximum relative activity of 130% was observed at 2.5% glutamine . Potassium showed a slight increase in activity of glutaminase especially at the concentration of 0.5 mM. While, frerric ions followed by ferrous showed the highest inhibition effect on glutaminase.