Ethylene Glycol Metabolism in the Acetogen Acetobacterium woodii
| Autor: | Kai Schuchmann, Dragan Trifunović, Volker Müller |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Ethylene Glycol 030106 microbiology Diol Microbiology Acetobacterium 03 medical and health sciences chemistry.chemical_compound Acetic acid Bacterial Proteins Bacterial microcompartment Molecular Biology Acetic Acid Ethanol biology Acetaldehyde Articles Gene Expression Regulation Bacterial Acetogen biology.organism_classification 030104 developmental biology Biochemistry chemistry Ethylene glycol |
| Zdroj: | Journal of Bacteriology. 198:1058-1065 |
| ISSN: | 1098-5530 0021-9193 |
| Popis: | The acetogenic bacterium Acetobacterium woodii is able to grow by the oxidation of diols, such as 1,2-propanediol, 2,3-butanediol, or ethylene glycol. Recent analyses demonstrated fundamentally different ways for oxidation of 1,2-propanediol and 2,3-butanediol. Here, we analyzed the metabolism of ethylene glycol. Our data demonstrate that ethylene glycol is dehydrated to acetaldehyde, which is then disproportionated to ethanol and acetyl coenzyme A (acetyl-CoA). The latter is further converted to acetate, and this pathway is coupled to ATP formation by substrate-level phosphorylation. Apparently, the product ethanol is in part further oxidized and the reducing equivalents are recycled by reduction of CO 2 to acetate in the Wood-Ljungdahl pathway. Biochemical data as well as the results of protein synthesis analysis are consistent with the hypothesis that the propane diol dehydratase (PduCDE) and CoA-dependent propionaldehyde dehydrogenase (PduP) proteins, encoded by the pdu gene cluster, also catalyze ethylene glycol dehydration to acetaldehyde and its CoA-dependent oxidation to acetyl-CoA. Moreover, genes encoding bacterial microcompartments as part of the pdu gene cluster are also expressed during growth on ethylene glycol, arguing for a dual function of the Pdu microcompartment system. IMPORTANCE Acetogenic bacteria are characterized by their ability to use CO 2 as a terminal electron acceptor by a specific pathway, the Wood-Ljungdahl pathway, enabling in most acetogens chemolithoautotrophic growth with H 2 and CO 2 . However, acetogens are very versatile and can use a wide variety of different substrates for growth. Here we report on the elucidation of the pathway for utilization of ethylene glycol by the model acetogen Acetobacterium woodii . This diol is degraded by dehydration to acetaldehyde followed by a disproportionation to acetate and ethanol. We present evidence that this pathway is catalyzed by the same enzyme system recently described for the utilization of 1,2-propanediol. The enzymes for ethylene glycol utilization seem to be encapsulated in protein compartments, known as bacterial microcompartments. |
| Databáze: | OpenAIRE |
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