[Effect of amn gene deletion on Corynebacterium glutamicum S9114 metabolism]

To study the effect of adenosine monophosphate nucleosidase gene deletion on Corynebacterium glutamicum S9114 metabolism.

We constructed the amn deficient strain A amn and studied its glutamate fermentation and acid tolerance.

Compared with the wild type strain, biomass of A amn strain increased by 16.2% whereas glutamate production reduced by 58.8%. After 10, 25 and 40 h, intracellular ATP level of A amn strain increased 3.0, 3.7 and 2.2 times. The isocitrate lyase activity increased by 17.1% , 4.9% and 44.5%, the isocitrate dehydrogenase activity decreased by 76.9%, 74.6% and 5.0%, and the glutamate dehydrogenase activity decreased by 42.4%, 50.8% and 42.4%. At pH4.0, the survival of Aamn strain dropped 64.9%. However, the intracellular ROS and protein carbonylation level showed an increase of 31.5% and 22.5% respectively.

Knocking out of amn gene enhanced intracellular ATP level and biomass formation, whereas had negative effect on glutamate fermentation and acid tolerance.