School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, China.
Bioresour Technol. 2010 Nov;101(22):8718-24. doi: 10.1016/j.biortech.2010.06.111. Epub 2010 Jul 15.
A strictly anaerobic, thermoacidophilic, H(2)-producing bacterium was isolated and designated as Thermoanaerobacterium aotearoense. The optimized cultivation conditions for H(2) production are 55 degrees C, pH 6.5 and 10gl(-1) of glucose or xylose. A metabolic pathway analysis showed that lactate occupied most of the liquid metabolites and consumed a large amount of NADH. To increase the efficiency of hydrogen production, the gene encoding the l-lactate dehydrogenase was knocked out to redirect the NADH flow. Genetic manipulation resulted in the 2 and 2.5 folds increase of the H(2) yield and production rate, respectively. The maximum H(2) yields using the Deltaldh mutant were 2.71, 1.45 and 2.28molH(2)mol(-1) sugar under glucose, xylose and glucose/xylose mixture tests, respectively. The recombinant Deltaldh strain could ferment the mixture of glucose and xylose to produce H(2) effectively, indicating that the performance of Thermoanaerobacterium in H(2) production can be significantly improved by metabolic engineering technique.
一株严格厌氧、嗜热嗜酸、产氢的细菌被分离出来并命名为嗜热厌氧杆菌。优化的产氢条件为 55°C、pH6.5 和 10gl(-1)的葡萄糖或木糖。代谢途径分析表明，乳酸占据了大部分液体代谢物，并消耗了大量的 NADH。为了提高氢气的生产效率，敲除了编码 l-乳酸脱氢酶的基因，以重新引导 NADH 的流动。遗传操作使氢气的产率和生产速率分别提高了 2 倍和 2.5 倍。使用 Deltaldh 突变体，在葡萄糖、木糖和葡萄糖/木糖混合物测试中，最大氢气产率分别为 2.71、1.45 和 2.28molH(2)mol(-1)糖。重组 Deltaldh 菌株可以有效地发酵葡萄糖和木糖的混合物来生产氢气，这表明通过代谢工程技术可以显著提高嗜热厌氧杆菌产氢的性能。
