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

摘要

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 ℃,Mn2+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/mL.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/mL for 30 h.A strategy for α-ketoglutaric acid (α-KG) production from L-glutamic acid by LGOX was developed.Under the optimal conditions,the yield of α-KG reached 91.2 g/L with the molar conversion ratio of 91.8% and production intensity 4.56 g/(L·h).