He Yaxue, Cassarini Chiara, Lens Piet N L
National University of Ireland Galway, Galway, Ireland.
Front Microbiol. 2021 Mar 10;12:647370. doi: 10.3389/fmicb.2021.647370. eCollection 2021.
CO fermentation by biocatalysis is a promising route for the sustainable production of valuable chemicals and fuels, such as acetic acid and ethanol. Considering the important role of environmental parameters on fermentation processes, granular sludge from an industrial anaerobic wastewater treatment system was tested as inoculum for ethanol production from H/CO at psychrophilic (18°C), submesophilic (25°C), and mesophilic (30°C) temperatures. The highest acetic acid and ethanol production was obtained at 25°C with a final concentration of 29.7 and 8.8 mM, respectively. The presence of bicarbonate enhanced acetic acid production 3.0 ∼ 4.1-fold, while inhibiting ethanol production. The addition of 0.3 g/L glucose induced butyric acid production (3.7 mM), while 5.7 mM ethanol was produced at the end of the incubation at pH 4 with glucose. The addition of 10 μM W enhanced ethanol production up to 3.8 and 7.0-fold compared to, respectively, 2 μM W addition and the control. The addition of 2 μM Mo enhanced ethanol production up to 8.1- and 5.4-fold compared to, respectively, 10 μM Mo and the control. This study showed that ethanol production from H/CO conversion using granular sludge as the inoculum can be optimized by selecting the operational temperature and by trace metal addition.
通过生物催化进行一氧化碳发酵是可持续生产有价值的化学品和燃料（如乙酸和乙醇）的一条有前景的途径。考虑到环境参数在发酵过程中的重要作用，对来自工业厌氧废水处理系统的颗粒污泥进行了测试，以作为在嗜冷（18°C）、亚中温（25°C）和中温（30°C）温度下由氢气/一氧化碳生产乙醇的接种物。在25°C时获得了最高的乙酸和乙醇产量，最终浓度分别为29.7 mM和8.8 mM。碳酸氢盐的存在使乙酸产量提高了3.0至4.1倍，同时抑制了乙醇的产生。添加0.3 g/L葡萄糖诱导产生了丁酸（3.7 mM），而在pH为4且添加葡萄糖的培养结束时产生了5.7 mM乙醇。与分别添加2 μM钨和对照相比，添加10 μM钨使乙醇产量分别提高了3.8倍和7.0倍。与分别添加10 μM钼和对照相比，添加2 μM钼使乙醇产量分别提高了8.1倍和5.4倍。这项研究表明，以颗粒污泥为接种物通过氢气/一氧化碳转化生产乙醇可以通过选择操作温度和添加微量金属来优化。
