土曲霉发酵过程中菌形和有机酸积累对产物合成的影响

Effect of Cell Morphology and Organic Acid Accumulation to Lovastatin Production by Aspergillus terreus

对土曲霉(Aspergillus terreus)产洛伐他汀过程中胞内外有机酸浓度进行测定,发现菌形对发酵过程胞内外有机酸浓度和洛伐他汀的产量有很大的影响。在发酵过程中形成球状菌比丝状菌更有利于洛伐他汀的合成,并且球状菌的胞内有机酸浓度普遍高于丝状菌。通过把有机酸与产素关联,发现在高产批次中胞内柠檬酸,α-酮戊二酸以及丙二酸大量积累,并且在产素期维持三羧酸循环的低通量能促进洛伐他汀高产。

Intracellular and extracellular organic acid concentrations of Aspergillus terreus product lovastatin were analyzed. It is found the cell morphology plays an important part on organic acid concentration and lovastatin production. The pellet morphology attains high lovastatin productivity, and the intracellular concentration of organic acid is higher than that of the filamentous morphology during the fermentation. The concentration of organic acid is associated with lovastatin production, and it is found that higher concentration of intracellular citric acid, α-ketoglutaric acid and malonic acid are important to lovastatin synthesis by keeping a low flux of tricarboxylic acid cycle during the producing period.