Fungi form a very diverse group of eukaryotes. The majority of investigated fungi contain mitochondria and are capable of oxidative phosphorylation. On the other hand, anaerobically functioning fungi, found as symbionts in the gastrointestinal tract of many herbivorous mammals, contain hydrogenosomes. These organelles of mitochondrial origin are also found in multiple classes of anaerobically functioning protists. Hydrogenosomes produce hydrogen as an endproduct of a fermentative energy metabolism and produce ATP by substrate-level phosphorylation. However, the hydrogenosomes of the anaerobic fungi Neocallimastix and Piromyces differ from the hydrogenosomes of trichomonads and those of anaerobic ciliates in the way they convert pyruvate to acetyl-CoA. The hydrogenosomes of these anaerobic fungi use pyruvate-formate lyase (PFL), whereas trichomonads use pyruvate-ferrodoxin oxidoreductase (PFO) and anaerobic ciliates use pyruvate dehydrogenase (PDH) for the degradation of pyruvate. The characteristics and role of these hydrogenosomes in the energy metabolis of anaerobic fungi is discussed.
Revised: October 23, 2019 |
Published: August 10, 2019
Citation
Hackstein J., S.E. Baker, J. Van Hellemond, J. Van Hellemond, and A. Tielens. 2019.Hydrogenosomes of Anaerobic Fungi: an Alternative Way to Adapt to Anaerobic Environments. In Hydrogenosomes and Mitosomes: Mitochondria of Anaerobic Eukaryotes, Second Edition. Microbiology Monographs, edited by J Tachezy. 159-175. Cham:Springer.PNNL-SA-146888.doi:10.1007/978-3-030-17941-0_7