Henstra Anne M, Stams Alfons J M
Centre for Biomolecular Sciences, University of Nottingham, University Park, NG7 2RD Nottingham, UK.
Int J Microbiol. 2011;2011:641582. doi: 10.1155/2011/641582. Epub 2011 Jul 7.
Carboxydothermus hydrogenoformans is a thermophilic strictly anaerobic bacterium that catalyses the water gas shift reaction, the conversion of carbon monoxide with water to molecular hydrogen and carbon dioxide. The thermodynamically favorable growth temperature, compared to existing industrial catalytic processes, makes this organism an interesting alternative for production of cheap hydrogen gas suitable to fuel CO-sensitive fuel cells in a future hydrogen economy, provided sufficiently low levels of CO are reached. Here we study CO conversion and final CO levels in cultures of C. hydrogenoformans grown in batch cultures that were started with a 100% CO gas phase with and without removal of formed CO(2). Final CO levels were 117 ppm without CO(2) removal and below 2 ppm with CO(2) removal. The Gibbs free energy change calculated with measured end concentrations and the detection of acetate suggest that C. hydrogenoformans shifted from a hydrogenogenic to an acetogenic metabolism.
嗜氢羧基热菌是一种嗜热严格厌氧菌，它催化水煤气变换反应，即将一氧化碳与水转化为分子氢和二氧化碳。与现有的工业催化过程相比，其在热力学上有利的生长温度，使得这种微生物成为在未来氢能经济中生产廉价氢气以适用于对一氧化碳敏感的燃料电池的一个有趣替代方案，前提是能够达到足够低的一氧化碳水平。在此，我们研究了在以100%一氧化碳气相开始的分批培养物中生长的嗜氢羧基热菌培养物中的一氧化碳转化和最终一氧化碳水平，培养过程中有无二氧化碳的去除。不去除二氧化碳时最终一氧化碳水平为117 ppm，去除二氧化碳时低于2 ppm。根据测得的终浓度计算的吉布斯自由能变化以及乙酸盐的检测表明，嗜氢羧基热菌从产氢代谢转变为产乙酸代谢。
