Bioproducts, Science, and Engineering Laboratory, Washington State University, Tri-Cities, 2710, Crimson Way, Richland, WA 99354, USA; Biological System Engineering Department, Washington State University, L. J. Smith Hall, Pullman, WA 99164, USA.
Bioproducts, Science, and Engineering Laboratory, Washington State University, Tri-Cities, 2710, Crimson Way, Richland, WA 99354, USA; Biological System Engineering Department, Washington State University, L. J. Smith Hall, Pullman, WA 99164, USA; Voiland School of Chemical Engineering and Bioengineering, Washington State University, Wegner Hall, Pullman, WA 99164, USA.
Bioresour Technol. 2024 Dec;414:131573. doi: 10.1016/j.biortech.2024.131573. Epub 2024 Oct 12.
Caproic acid is an important compound for producing a variety of chemicals and a potential precursor for Sustainable Aviation Fuels (SAF). This study aimed at developing a stable mixed culture producing caproic acid using short-chain carboxylic acids (SCCAs) derived from arrested anaerobic digestion (AAD) of green waste and optimizing chain elongation (CE) conditions. The results showed that the mixed culture was dominated by Clostridium sensu stricto 12 (53.09 %), optimally producing caproic acid at 37 °C, pH 7.20, with a 15 % inoculum concentration. Under these conditions, 75.59 % of the consumed electrons contributed to caproic acid formation. Gradual ethanol feeding in bioreactor experiments resulted in caproic acid titer of 13.36 g/L, with carbon conversion efficiency (CCE) of 81.91 % and electron transfer efficiency (ETE) of 76.39 %, surpassing batch experiments without gradual ethanol addition. These findings demonstrate that the effectiveness of a mixed culture can be improved, resulting in increased caproic acid production.
己酸是一种重要的化合物，可用于生产各种化学品，也是可持续航空燃料（SAF）的潜在前体。本研究旨在开发一种使用源自绿废物停滞厌氧消化（AAD）的短链羧酸（SCCA）生产己酸的稳定混合培养物，并优化链延伸（CE）条件。结果表明，混合培养物以严格梭菌 12 属（53.09％）为主，在 37°C、pH7.20 和 15％接种浓度下，最优地生产己酸。在这些条件下，消耗的电子中有 75.59％用于己酸的形成。在生物反应器实验中逐渐添加乙醇，己酸的产量达到 13.36g/L，碳转化率（CCE）为 81.91％，电子传递效率（ETE）为 76.39％，超过了没有逐渐添加乙醇的分批实验。这些发现表明，混合培养物的有效性可以提高，从而增加己酸的产量。
