Hüsemann M H, Papoutsakis E T
Department of Chemical Engineering, Rice University, Houston, Texas 77251.
Appl Environ Microbiol. 1990 May;56(5):1497-500. doi: 10.1128/aem.56.5.1497-1500.1990.
Addition of acetate or propionate to uncontrolled-pH batch cultures does not affect the initiation of solventogenesis but does enhance final solvent concentrations compared with those of unchallenged cultures. This observation can be explained in terms of the increased buffering capacity of the medium brought about by the added acids, resulting in protection against premature growth inhibition due to low culture pH values at the end of the fermentation. The uptake of propionic acid from the medium does not proceed solely via the coenzyme A-transferase pathway, since less acetone than propanol is formed. Therefore, at least 50% of the propionic acid is taken up through the reversed kinase-phosphotransbutyrylase reaction pathway.
在未控制pH值的分批培养中添加乙酸盐或丙酸盐，不会影响溶剂生成的起始，但与未添加的培养物相比，确实会提高最终的溶剂浓度。这一观察结果可以用添加的酸导致培养基缓冲能力增强来解释，从而防止由于发酵结束时培养物pH值低而导致的过早生长抑制。丙酸从培养基中的吸收并非仅通过辅酶A转移酶途径进行，因为生成的丙酮比丙醇少。因此，至少50%的丙酸是通过逆向激酶-磷酸转丁酰酶反应途径吸收的。
