Department of Chemical Engineering, Hanyang University, 222, Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
Korea Institute of Ceramic Engineering and Technology (KICET), 202, Osongsaengmyeong 1-ro, Heungdeck-gu, Cheongju-si, Chungcheongbuk-do 28160, Republic of Korea.
Bioresour Technol. 2022 Feb;346:126660. doi: 10.1016/j.biortech.2021.126660. Epub 2021 Dec 30.
Megasphaera hexnaoica is anaerobic bacteria who has well running reverse β-oxidation pathway. In previous study, the strain showed excellent production of medium chain carboxylic acids (MCCAs) using fructose as electron donor. In this study, chain elongation process study using lactate instead of fructose was conducted in M. hexnaoica fermentation. It was found that M. hexanoica can use lactate as electron donor in chain elongation process. 8.9 g/L caproate production was achieved in fermentation using lactate as sole electron donor. Compare to fructose condition, lactate as electron donor showed more than 3 times higher specific titer and specific productivity. In addition, when fructose and lactate were used as electron donor simultaneously, further improvement of MCCAs production was observed to achieve maximum caproate productivity of 20.9 g/L/day. Utilization of lactate as electron donor in M. hexanoica showed potential opportunity in chain elongation process.
巨球形菌是一种厌氧细菌，具有良好的反向β-氧化途径。在之前的研究中，该菌株使用果糖作为电子供体显示出了优异的中链羧酸（MCCAs）生产能力。在本研究中，使用乳酸代替果糖在 M. hexnaoica 发酵中进行了链延伸过程的研究。结果发现，M. hexanoica 可以在链延伸过程中使用乳酸作为电子供体。在以乳酸为唯一电子供体的发酵中，可获得 8.9 g/L 的己酸产量。与果糖条件相比，乳酸作为电子供体显示出超过 3 倍的更高的比产率和比生产力。此外，当同时使用果糖和乳酸作为电子供体时，观察到 MCCAs 产量进一步提高，达到 20.9 g/L/天的最大己酸生产力。在 M. hexanoica 中使用乳酸作为电子供体在链延伸过程中显示出了潜在的机会。
