Leigh John A
Department of Microbiology, University of Washington, Seattle, Washington, USA.
Methods Enzymol. 2011;494:111-8. doi: 10.1016/B978-0-12-385112-3.00006-8.
Hydrogen (H(2)) is a primary electron donor for methanogenesis and its availability can have profound effects on gene expression and the physiology of energy conservation. The rigorous evaluation of the effects of hydrogen conditions requires the comparison of cultures that are grown under hydrogen limitation and hydrogen excess. The growth of methanogens under defined hydrogen conditions is complicated by the dynamics of hydrogen dissolution and its utilization by the cells. In batch culture, gassing and agitation conditions must be carefully calibrated, and even then variations in growth rate and cell density are hard to avoid. Using chemostats, continuous cultures can be achieved whose nutritional states are known, while growth rate and cell density are invariant. Cultures whose growth is limited by hydrogen can be compared to cultures whose growth is limited by some other nutrient and are therefore under hydrogen excess.
氢气（H₂）是产甲烷过程中的主要电子供体，其可利用性会对基因表达和能量守恒生理过程产生深远影响。要严格评估氢气条件的影响，需要比较在氢气限制和氢气过量条件下培养的微生物。在特定氢气条件下产甲烷菌的生长因氢气溶解动力学及其被细胞利用的情况而变得复杂。在分批培养中，通气和搅拌条件必须仔细校准，即便如此，生长速率和细胞密度的变化仍难以避免。使用恒化器，可以实现营养状态已知的连续培养，同时生长速率和细胞密度保持不变。生长受氢气限制的培养物可与生长受其他某种营养物质限制因而处于氢气过量状态的培养物进行比较。
