Fermentation in high glucose is a common strategy to improve the product concentration in industry. However,natural strains can not withstand high glucose. With the aim of elucidating the effects of high glucose on physiological metabolism of fumaric acid producer Rhizopus oryzae,membrane fatty acid composition, intracellular adenosine triphosphate (ATP) level,and the salicylhy⁃droxamic acid sensitivity respiration of the parent strain and the high⁃glucose resistant strain were determined and compared at different glucose concentrations. Compared to that of the parent strain, the high⁃glucose resistant strain exhibited higher content of the unsaturated fatty acids and higher membrane fluidity,higher ATP level and stronger salicylhy⁃droxmic acid sensitivity respiration. To compensate the deficiencies in metabolic of the parent strain, C/N ratio was adjusted or glycine was added. In fermentation with 150 g/L glucose medium,and 500 C/N, fumaric acid could increase from 37�4 to 40�2 g/L. The addition of 0�5 g/L glycine also improved the productivity of fumaric acid by 17�1%, it increased to 43�8 g/L.%高糖发酵是提高产物浓度的常用方法，但天然菌株不能耐受高的糖浓度。为了解析高糖环境对菌株生理代谢的影响，以驯化获得的耐高糖菌株和原始菌株为对象，研究不同糖浓度对二者生理特性的影响。结果发现：与原始菌株相比，耐高糖菌株细胞膜不饱和脂肪酸的含量、胞内三磷酸腺苷（ ATP ）含量较高，且表现出更强的侧系呼吸强度。在此基础上，尝试通过调节碳氮比（ C／N）或添加甘氨酸的方式补足原始菌株的代谢不足。结果表明：在150 g／L糖质量浓度条件下，调节C／N为500时，原始菌株富马酸产量可由37�4 g／L增至40�2 g／L。而添加0�5 g／L甘氨酸，原始菌株富马酸产量可以增至43�8 g／L，提高了17�1％。
展开▼
