3-磷酸甘油醛脱氢酶促进谷氨酸棒杆菌发酵生产L-精氨酸和L-鸟氨酸

Glyceraldehyde-3-phosphate dehydrogenase promotes the production of L-arginine and L-ornithine by Corynebacterium glutamicum

在谷氨酸棒状杆菌( Corynebacterium glutamicum )SNK118中表达NADP +依赖型的3-磷酸甘油醛脱氢酶编码基因,提高胞内NADPH水平,以提高 L -精氨酸( L -Arginine)和 L -鸟氨酸(L-Ornithine)发酵产量。通过NCBI数据库检索,选取了3个不同来源的3-磷酸甘油醛脱氢酶编码基因。经测定酶活力,最终选择糖丁基梭菌( Clostridium saccharobutylicum) DSM13864来源的NADP +依赖型的3-磷酸甘油醛脱氢酶基因( CsgapC )。构建了产 L -精氨酸的重组菌SNK118/pXMJ19- CsgapC,当摇瓶发酵70 h时产 L -精氨酸11.55 g/L,糖酸转化率0.13 g/g,与对照菌SNK118/pXMJ19相比,精氨酸产量和糖酸转化率分别提高了26%和10.2%。在 L -鸟氨酸生产菌株SNK118Δ argF Δ argR 中重组表达 CsgapC,重组菌SNK118Δ argF Δ argR /pXMJ19- CsgapC 摇瓶发酵70 h产 L -鸟氨酸27.76 g/L,糖酸转化率0.274 g/g,与对照菌SNK118Δ argF Δ argR /pXMJ19相比, L -鸟氨酸产量和糖酸转化率分别提高了20.1%和15.6%。结果表明,异源表达 CsgapC 有助于提高谷氨酸棒杆菌发酵生产 L -精氨酸和 L -鸟氨酸的水平。

NADP +-dependent glyceraldehyde-3-phosphate dehydrogenase encoding gene was expressed in Corynebacterium glutamicum SNK118 to increase intracellular NADPH level to further increase the yields of L -arginine and L -ornithine. Clostridium saccharobutylicum DSM13864 -derived NADP +-dependent glyceraldehyde-3-phosphate dehydrogenase gene ( CsgapC ) was selected and expressed in C. glutamicum . The recombinant strain SNK118/pXMJ19-CsgapC produced11.55 g/L L -arginine and the conversion rate of glucose was 0.13 g/g after 70 h flask fermentation, which were26% and10.2% higher than that of the control, respectively. Moreover, CsgapC was also introduced into L - ornithine-producing strain SNK118ΔargFΔargR to obtain a recombinant strain SNK118ΔargFΔargR/pXMJ19-CsgapC. During 70 h flask fermentation,27.76 g/L L -ornithine with 0.274 g/g conversion rate were achieved, which were20.1% and15.6% higher than those of the control, respectively. This study therefore concluded that heterologously express CsgapC promotes the production of L -arginine and L -ornithine by C. glutamicum.