Jones Edmunds, Gainesville, FL 32606, USA.
Water Res. 2010 Mar;44(6):1819-24. doi: 10.1016/j.watres.2009.12.004. Epub 2010 Jan 4.
Denitrifying bacteria that are switched from oxic to anoxic conditions can experience diauxic lag, which is the time required for re-synthesis of nitrate reductase and other denitrifying enzymes. Pseudomonas denitrificans were exposed to alternating oxic/anoxic phases in a continuous flow reactor with either 4-h or 8-h anoxic phase lengths, in comparison to a measured diauxic lag of 9.5h following steady-state oxic conditions. The P. denitrificans were unable to sustain anoxic growth at either of the anoxic phase lengths tested. Diauxic lag observed after several cycles of alternating oxic/anoxic phases was significantly longer than the diauxic lag measured after steady-state oxic conditions. This may be attributed to increase of cell maintenance energy requirements due to substrate accumulation during anoxic phases and concomitant high specific growth rates during oxic phases.
在好氧条件下切换到缺氧条件的反硝化细菌可能会经历兼性营养延迟，这是重新合成硝酸还原酶和其他反硝化酶所需的时间。与稳态好氧条件下的 9.5 小时兼性营养延迟相比，将 Pseudomonas denitrificans 暴露于连续流动反应器中的 4 小时或 8 小时缺氧阶段交替中。在测试的两种缺氧阶段长度下，P. denitrificans均无法维持缺氧生长。在几次好氧/缺氧交替循环后观察到的兼性营养延迟明显长于稳态好氧条件下测量的兼性营养延迟。这可能是由于缺氧阶段底物积累和同时好氧阶段高比生长速率导致细胞维持能量需求增加所致。
