Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Max-von-Laue Str. 9, D-60438, Frankfurt, Germany.
Environ Microbiol. 2018 Dec;20(12):4512-4525. doi: 10.1111/1462-2920.14389. Epub 2018 Oct 5.
The quarternary, trimethylated amine glycine betaine (GB) is widespread in nature but its fate under anoxic conditions remains elusive. It can be used by some acetogenic bacteria as carbon and energy source but the pathway of GB metabolism has not been elucidated. We have identified a gene cluster involved in GB metabolism and studied acetogenesis from GB in the model acetogen Acetobacterium woodii. GB is taken up by a secondary active, Na coupled transporter of the betaine-choline-carnitine (BCC) family. GB is demethylated to dimethylglycine, the end product of the reaction, by a methyltransferase system. Further conversion of the methyl group requires CO as well as Na indicating that GB metabolism involves the Wood-Ljungdahl pathway. These studies culminate in a model for the path of carbon and electrons during acetogenensis from GB and a model for the bioenergetics of acetogenesis from GB.
季铵、三甲基胺甘氨酸甜菜碱（GB）广泛存在于自然界中，但在缺氧条件下的命运仍然难以捉摸。它可以被一些产乙酸细菌用作碳和能源源，但 GB 代谢途径尚未阐明。我们已经鉴定出参与 GB 代谢的基因簇，并研究了模型产乙酸菌伍德氏醋酸杆菌（Acetobacterium woodii）从 GB 进行产乙酸作用。GB 通过甜菜碱-胆碱-肉碱（BCC）家族的二次主动 Na 偶联转运蛋白摄取。GB 被甲基转移酶系统甲基化为二甲氨基乙酸，反应的终产物。进一步转化甲基需要 CO 和 Na，表明 GB 代谢涉及伍德-吕格达尔途径。这些研究最终提出了从 GB 进行产乙酸作用时碳和电子途径的模型，以及从 GB 进行产乙酸作用时生物能量学的模型。
