谷氨酸氧化酶高产菌株的筛选鉴定及催化生产α-酮戊二酸

Screening and identification of high yield strain of glutamate oxidase and its enzymatic production of α-ketoglutarate

采用简易的偶联终点显色反应(Trinder显色反应),从土壤中分离出高产谷氨酸氧化酶(LGOX)的菌株不透明红球菌Rhodococcus opacus FMME1-41,并对此菌株的产酶特性进行研究。结果表明:该菌株所产LGOX主要分泌在发酵液中,对L-谷氨酸具有较强的底物专一性,最适pH 6.5,最适温度为35℃,Mn^(2+)是该酶的激活剂。通过发酵培养基优化,培养30 h时LGOX活力达到6.4 U/m L。利用该酶转化L-谷氨酸生产α-酮戊二酸,在最佳转化条件下转化20 h,α-酮戊二酸产量达到91.2 g/L,转化率为91.8%,α-KG生产强度为4.56 g/(L·h)。

Using a simple Trinder color reaction,the high yield glutamate oxidase （ LGOX ） strain Rhodococcus opacus FMME 1-41 was obtained from soil.The enzymatic properties of R. opacus FMME 1-41 were studied. LGOX was an extracellular enzyme,its optimal pH was 6. 5 and optimal temperature was 35 ^. L-glutamate is specific substrate of the LGOX . LGOX could be activated by Mn2＋. After medium optimization, LGOX activity could reach 6.4 U / m L for 30 h.A strategy for a-ketoglutaric acid （a - K G ） production from L-glutamic acid by LGOX was developed.Under the optimal conditions,the yield of a-KG reached 91. 2 g/L with the molar conversion ratio of 91. 8 % and production intensity 4. 56 g/（L ＊h ）.