Bioengineering and Environmental Science Lab, Department of Energy and Environmental Engineering, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500 007, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India.
Bioengineering and Environmental Science Lab, Department of Energy and Environmental Engineering, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, 500 007, India; Academy of Scientific & Innovative Research (AcSIR), Ghaziabad, 201002, India.
Chemosphere. 2023 Jul;328:138491. doi: 10.1016/j.chemosphere.2023.138491. Epub 2023 Mar 22.
The functional role of lactate (H), as a co-substrate along with glucose (Glu) as well as an electron donor for the synthesis of caproic acid (H), a medium chain fatty acid (MCFAs) was studied. A varied H and Glu ratios were thus investigated in fed-batch anaerobic reactors (R1-R5) operated at pH 6 with a heat-treated anaerobic consortium. R1 and R5 were noted as controls and operated with sole Glu and H, respectively. Strategically, ethanol (H) was additionally supplemented as co-electron donor after the production of short chain carboxylic acids (SCCAs) for chain elongation in all the reactors. The reactor operated with H and Glu in a ratio of 0.25:0.75 (1.25 g/L (H) and 3.75 g/L (Glu)) showed the highest H production of 1.86 g/L. R5 operated with solely H yielded propionic acid (H) as the major product which further led to the higher valeric acid (H) production of 1.1 g/L within the reactor. Butyric acid (H) was observed in R1, which used Glu as carbon source alone indicating the importance of H as electron co-donor. Clostridium observed as the most dominant genera in shotgun metagenome sequencing in R2 and R3, the reactors that produced the highest H in comparison to other studied reactors. The study thus provided insight into the importance of substrate and electron donor and their supplementation strategies during the production of MCFAs.
研究了乳酸盐（H）作为共底物与葡萄糖（Glu）以及电子供体在合成己酸（H），一种中链脂肪酸（MCFAs）中的功能作用。因此，在 pH 值为 6 的分批厌氧反应器（R1-R5）中研究了不同的 H 和 Glu 比例，该反应器使用热处理的厌氧混合物运行。R1 和 R5 分别作为对照，仅使用 Glu 和 H 运行。策略上，在所有反应器中，在短链羧酸（SCCA）生产后，额外补充乙醇（H）作为共电子供体，以进行链延长。在 H 和 Glu 的比例为 0.25:0.75（1.25 g/L（H）和 3.75 g/L（Glu））的反应器中，H 的产量最高，为 1.86 g/L。仅使用 H 运行的 R5 产生丙酸（H）作为主要产物，这进一步导致反应器中产生 1.1 g/L 的更高的戊酸（H）产量。在仅使用 Glu 作为碳源的 R1 中观察到丁酸（H），这表明 H 作为电子共供体的重要性。在 R2 和 R3 中的 shotgun 宏基因组测序中观察到梭菌属作为最占优势的属，与其他研究的反应器相比，这两个反应器产生的 H 最高。因此，该研究深入了解了 MCFAs 生产过程中底物和电子供体及其补充策略的重要性。
