Entner–Doudoroff pathway

The Entner–Doudoroff pathway describes an alternate series of reactions that catabolize glucose to pyruvate using a set of enzymes different from those used in either glycolysis or the pentose phosphate pathway. Most bacteria use glycolysis and the pentose phosphate pathway. This pathway was first reported in 1952 by Michael Doudoroff (1911–1975) and Nathan Entner.^[1]

Distinct features of the Entner–Doudoroff pathway are that it:

• Occurs only in prokaryotes.

• Uses 6-phosphogluconate dehydrase and 2-keto-3-deoxyphosphogluconate aldolase to create pyruvates from glucose.

• Has a net yield of 1 ATP for every glucose molecule processed, as well as 1 NADH and 1 NADPH. By comparison, glycolysis has a net yield of 2 ATP and 2 NADH for every one glucose molecule processed.

Organisms that utilize the Entner-Doudoroff pathway

There are a few bacteria that substitute classic glycolysis with the Entner-Doudoroff Pathway. They may lack enzymes essential for glycolysis, such as phosphofructokinase-1. This pathway is generally found in Pseudomonas, Rhizobium, Azotobacter, Agrobacterium, and a few other gram-negative genera. Very few gram-positive bacteria have this pathway, with Enterococcus faecalis being a rare exception.^[2] Most organisms that use the pathway are aerobes due to the low ATP yield per glucose.^[3]

• Pseudomonas,^[4] a genus of Gram-negative bacteria
• Azotobacter,^[5] a genus of Gram-negative bacteria
• Rhizobium,^[6] a genus of Gram-negative bacteria
• Agrobacterium,^[7] a genus of Gram-negative bacteria
• Escherichia coli,^[4] a Gram-negative bacterium
• Enterococcus faecalis,^[8] a Gram-positive bacterium
• Zymomonas mobilis,^[3] a Gram-negative facultative anaerobe
• Xanthomonas campestris,^[9] a Gram negative bacterium which uses this pathway as main pathway for providing energy.

References

1. ^ Entner, N., and Doudoroff, M. (1952) J.Biol.Chem. 196, 853 - 862
2. ^ Willey, Sherwood, Woolverton.. Prescott's Principles of Microbiology. 
3. ^ ^{a b} Zymomonas mobilis
4. ^ ^{a b} Peekhaus N, Conway T (1998). "What's for dinner?: Entner-Doudoroff metabolism in Escherichia coli.". J Bacteriol 180 (14): 3495–502. PMC 107313. PMID 9657988. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=107313. 
5. ^ Michael P. Stephenson, Frank A. Jackson and Edwin A. Dawes (1978). "Further Observations on Carbohydrate Metabolism and its Regulation in Azotobacter beijerinckii". Journal of General Microbiology 109 (1): 89–96. doi:10.1099/00221287. http://mic.sgmjournals.org/cgi/content/abstract/109/1/89. 
6. ^ Don J.. Brenner; George M.. Garrity; Noel R.. Krieg; James T.. Staley (2005). proteobacteria: The alpha-, beta-, delta-, and epsilonproteobacteria. Springer Science. pp. 326–327. ISBN 9780387241456. http://books.google.com/books?id=9cwgo-9IyTUC&pg=PA326. Retrieved 29 December 2010. 
7. ^ Arthur LO, Nakamura LK, Julian G, Bulla LA (1975). "Carbohydrate catabolism of selected strains in the genus Agrobacterium.". Appl Microbiol 30 (5): 731–7. PMC 187263. PMID 128316. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=187263. 
8. ^ GODDARD JL, SOKATCH JR (1964). "2-KETOGLUCONATE FERMENTATION BY STREPTOCOCCUS FAECALIS.". J Bacteriol 87: 844–51. PMC 277103. PMID 14137623. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=277103. 
9. ^ Lu GT, Xie JR, Chen L, Hu JR, An SQ, Su HZ et al. (2009). "Glyceraldehyde-3-phosphate dehydrogenase of Xanthomonas campestris pv. campestris is required for extracellular polysaccharide production and full virulence.". Microbiology 155 (Pt 5): 1602–12. doi:10.1099/mic.0.023762-0. PMID 19372163. http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19372163.