In this study, a compound nitrogen source, integrating the advantages of ammonium acetate and soybean meal, was proposed to further improve acetone-butanol-ethanol fermentation. Unfortunately, this compound nitrogen source was found to effectively inhibit cellular performance, as the introduction of NH₄⁺ significantly decreased the yield of butanol and total solvents by 34.78% and 35.14%, to only 6.62 g/L and 10.76 g/L, respectively. Meanwhile, the regulatory mechanism was further elucidated at different levels. As a result, the NH₄⁺ could down-regulate the transcriptional levels of key genes involved in butanol synthesis, and the activity of acetoacetyl-CoA/acyl-CoA transferase, and then decrease the accumulation of key intermediates. Therefore, ammonium acetate has a dual function in ABE fermentation, as it effectively improves ABE fermentation when it is the sole nitrogen source but significantly decreases fermentation performance in the presence of soybean meal, broadening the understanding of nitrogen regulation mechanism of C. acetobutylicum.

在这项研究中，提出了一种结合乙酸铵和豆粕优点的复合氮源，以进一步改善丙酮-丁醇-乙醇发酵。不幸的是，发现这种复合氮源可有效抑制细胞性能，因为引入NH ₄ ^+会显着降低丁醇和总溶剂的收率，分别降低34.78％和35.14％，分别降至6.62 g / L和10.76 g / L。 。同时，在不同层次上进一步阐明了调控机制。结果，NH ₄ ⁺可能下调参与丁醇合成的关键基因的转录水平以及乙酰乙酰辅酶A /酰基辅酶A转移酶的活性，从而减少关键中间体的积累。因此，乙酸铵在ABE发酵中具有双重功能，因为当它是唯一的氮源时，它可以有效地改善ABE发酵，但是在存在豆粕的情况下会大大降低发酵性能，从而拓宽了丙酮丁醇梭菌对氮调节机制的认识。