Aerobic and anaerobic bacteria can be identified by growing them in test tubes of thioglycolate broth: 1: Obligate aerobes need oxygen because they cannot ferment or respire anaerobically. They gather at the top of the tube where the oxygen concentration is highest. 2: Obligate anaerobes are poisoned by oxygen, so they gather at the bottom of the tube where the oxygen concentration is lowest. 3: Facultative anaerobes can grow with or without oxygen because they can metabolise energy aerobically or anaerobically. They gather mostly at the top because aerobic respiration generates more ATP than fermentation. 4: Microaerophiles need oxygen because they cannot ferment or respire anaerobically. However, they are poisoned by high concentrations of oxygen. They gather in the upper part of the test tube but not the very top. 5: Aerotolerant anaerobes do not require oxygen as they use fermentation to make ATP. Unlike obligate anaerobes, they are not poisoned by oxygen. They can be found evenly spread throughout the test tube.
It has been observed that in mutants of Salmonella typhimurium that underwent mutations to be either obligate aerobes or anaerobes, there were varying levels of chromatin-remodeling proteins. The obligate aerobes were later found to have a defective DNA gyrase subunit A gene (gyrA), while obligate anaerobes were defective in topoisomerase I (topI). This indicates that topoisomerase I and its associated relaxation of chromosomal DNA is required for transcription of genes required for aerobic growth, while the opposite is true for DNA gyrase.[7] Additionally, in Escherichia coli K-12 it has been noted that phosphofructokinase (PFK) exists as a dimer under aerobic conditions and as a tetramer under anaerobic conditions. Given PFK’s role in glycolysis, this has implications for the effect of oxygen on the glucose metabolism of E. coli K-12 in relation to the mechanism of the Pasteur effect.[8][9]
There may exist a core network of transcription factors (TFs) that includes the major oxygen-responsive ArcA and FNR control the adaptation of Escherichia coli to changes in oxygen availability. Activities of these two regulators are indicative of spatial effects that may affect gene expression in the microaerobic range. It has also been observed that these oxygen-sensitive proteins are protected within the cytoplasm by oxygen consumers within the cell membrane, known as terminal oxidases.[10]
Facultative anaerobes are able to grow in both the presence and absence of oxygen due to the expression of both aerobic and anaerobic respiratory chains using either oxygen or an alternative electron acceptor.[11] For example, in the absence of oxygen, E. coli can use fumarate, nitrate, nitrite, dimethyl sulfoxide, or trimethylamine oxide as an electron acceptor.[11] This flexibility allows facultative anaerobes to survive in a number of environments, and in environments with frequently changing conditions.[1]
Several species of protists use a facultative anaerobic metabolism to enhance their ATP production, and some can produce dihydrogen through this process.[12]
As pathogensedit
Since facultative anaerobes are able to grow in both the presence and absence of oxygen, they can survive in many different environments, adapt easily to changing conditions, and thus have a selective advantage over other bacteria. As a result, most life-threatening pathogens are facultative anaerobes.[1]
The ability of facultative anaerobic pathogens to survive without oxygen is important since their infection is shown to reduce oxygen levels in their host's gut tissue.[13] Moreover, the ability of facultative anaerobes to limit oxygen levels at infection sites is beneficial to them and other bacteria, as dioxygen can form reactive oxygen species (ROS). These species are toxic to bacteria and can damage their DNA, among other constituents.[1]
^Ryan KJ; Ray CG, eds. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. pp. 261–271, 273–296. ISBN0-8385-8529-9.
^Singleton P (1999). Bacteria in Biology, Biotechnology and Medicine (5th ed.). Wiley. pp. 444–454. ISBN0-471-98880-4.
^Carlile MJ, Watkinson SC, Gooday GW (2001). The Fungi (2nd ed.). Academic Press. pp. 85–105. ISBN0-12-738446-4.
^Schöttler, U. (November 30, 1979). "On the Anaerobic Metabolism of Three Species of Nereis (Annelida)" (PDF). Marine Ecology Progress Series. 1: 249–54. Bibcode:1979MEPS....1..249S. doi:10.3354/meps001249. ISSN 1616-1599. Retrieved February 14, 2010.
^Yamamoto, N., & Droffner, M. L. (1985). Mechanisms determining aerobic or anaerobic growth in the facultative anaerobe Salmonella typhimurium. Proceedings of the National Academy of Sciences, 82(7), 2077-2081. https://doi.org/10.1073/pnas.82.7.2077
^Doelle, H. W. (1974). Dimeric and tetrameric phosphofructokinase and the Pasteur effect in Escherichia coli K-12. FEBS Lett, 49(2), 220-222. PII: 0014-5793(74)80516-8 (core.ac.uk)
^Pasteur L (1857). "Mémoire sur la fermentation applée lactique" [Dissertation on the fermentation called lactic]. Comptes rendus de l'Académie des Sciences (in French). 45 (913–916): 1032–1036.
^Rolfe, M. D., Ocone, A., Stapleton, M. R., Hall, S., Trotter, E. W., Poole, R. K., ... & Green, J. (2012). Systems analysis of transcription factor activities in environments with stable and dynamic oxygen concentrations. Open biology, 2(7), 120091. https://doi.org/10.1098/rsob.120091
^ abUnden, Gottfried; Trageser, Martin (1991). "Oxygen regulated gene expression in Escherichia coli: Control of anaerobic respiration by the FNR protein". Antonie van Leeuwenhoek. 59 (2): 65–76. doi:10.1007/BF00445650. ISSN 0003-6072. PMID 1854188. S2CID 33083164.
^Ginger, Michael L.; Fritz-Laylin, Lillian K.; Fulton, Chandler; Cande, W. Zacheus; Dawson, Scott C. (2010-12-01). "Intermediary Metabolism in Protists: a Sequence-based View of Facultative Anaerobic Metabolism in Evolutionarily Diverse Eukaryotes". Protist. 161 (5): 642–671. doi:10.1016/j.protis.2010.09.001. ISSN 1434-4610. PMC3021972. PMID 21036663.
^Jennewein, Jonas; Matuszak, Jasmin; Walter, Steffi; Felmy, Boas; Gendera, Kathrin; Schatz, Valentin; Nowottny, Monika; Liebsch, Gregor; Hensel, Michael; Hardt, Wolf-Dietrich; Gerlach, Roman G.; Jantsch, Jonathan (December 2015). "Low-oxygen tensions found in S almonella -infected gut tissue boost S almonella replication in macrophages by impairing antimicrobial activity and augmenting S almonella virulence: Hypoxia and Salmonella replication". Cellular Microbiology. 17 (12): 1833–1847. doi:10.1111/cmi.12476. PMID 26104016.
External linksedit
Anaerobic Bacteria and Anaerobic Bacteria in the decomposition (stabilization) of organic matter. 2009-02-05 at the Wayback Machine
May 04, 2024
facultative, anaerobic, organism, facultative, anaerobic, organism, organism, that, makes, aerobic, respiration, oxygen, present, capable, switching, fermentation, oxygen, absent, aerobic, anaerobic, bacteria, identified, growing, them, test, tubes, thioglycol. A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present but is capable of switching to fermentation if oxygen is absent 1 2 Aerobic and anaerobic bacteria can be identified by growing them in test tubes of thioglycolate broth 1 Obligate aerobes need oxygen because they cannot ferment or respire anaerobically They gather at the top of the tube where the oxygen concentration is highest 2 Obligate anaerobes are poisoned by oxygen so they gather at the bottom of the tube where the oxygen concentration is lowest 3 Facultative anaerobes can grow with or without oxygen because they can metabolise energy aerobically or anaerobically They gather mostly at the top because aerobic respiration generates more ATP than fermentation 4 Microaerophiles need oxygen because they cannot ferment or respire anaerobically However they are poisoned by high concentrations of oxygen They gather in the upper part of the test tube but not the very top 5 Aerotolerant anaerobes do not require oxygen as they use fermentation to make ATP Unlike obligate anaerobes they are not poisoned by oxygen They can be found evenly spread throughout the test tube Some examples of facultatively anaerobic bacteria are Staphylococcus spp 3 Escherichia coli Salmonella Listeria spp 4 Shewanella oneidensis and Yersinia pestis Certain eukaryotes are also facultative anaerobes including fungi such as Saccharomyces cerevisiae 5 and many aquatic invertebrates such as nereid polychaetes 6 It has been observed that in mutants of Salmonella typhimurium that underwent mutations to be either obligate aerobes or anaerobes there were varying levels of chromatin remodeling proteins The obligate aerobes were later found to have a defective DNA gyrase subunit A gene gyrA while obligate anaerobes were defective in topoisomerase I topI This indicates that topoisomerase I and its associated relaxation of chromosomal DNA is required for transcription of genes required for aerobic growth while the opposite is true for DNA gyrase 7 Additionally in Escherichia coli K 12 it has been noted that phosphofructokinase PFK exists as a dimer under aerobic conditions and as a tetramer under anaerobic conditions Given PFK s role in glycolysis this has implications for the effect of oxygen on the glucose metabolism of E coli K 12 in relation to the mechanism of the Pasteur effect 8 9 There may exist a core network of transcription factors TFs that includes the major oxygen responsive ArcA and FNR control the adaptation of Escherichia coli to changes in oxygen availability Activities of these two regulators are indicative of spatial effects that may affect gene expression in the microaerobic range It has also been observed that these oxygen sensitive proteins are protected within the cytoplasm by oxygen consumers within the cell membrane known as terminal oxidases 10 Contents 1 Functions 2 As pathogens 3 See also 4 References 5 External linksFunctions editFacultative anaerobes are able to grow in both the presence and absence of oxygen due to the expression of both aerobic and anaerobic respiratory chains using either oxygen or an alternative electron acceptor 11 For example in the absence of oxygen E coli can use fumarate nitrate nitrite dimethyl sulfoxide or trimethylamine oxide as an electron acceptor 11 This flexibility allows facultative anaerobes to survive in a number of environments and in environments with frequently changing conditions 1 Several species of protists use a facultative anaerobic metabolism to enhance their ATP production and some can produce dihydrogen through this process 12 As pathogens editSince facultative anaerobes are able to grow in both the presence and absence of oxygen they can survive in many different environments adapt easily to changing conditions and thus have a selective advantage over other bacteria As a result most life threatening pathogens are facultative anaerobes 1 The ability of facultative anaerobic pathogens to survive without oxygen is important since their infection is shown to reduce oxygen levels in their host s gut tissue 13 Moreover the ability of facultative anaerobes to limit oxygen levels at infection sites is beneficial to them and other bacteria as dioxygen can form reactive oxygen species ROS These species are toxic to bacteria and can damage their DNA among other constituents 1 nbsp a Escherichia coli nbsp b Salmonella nbsp c Streptococcus pneumoniae nbsp d Haemophilus influenzaeExamples of pathogenic facultative anaerobes See also editAerobic respiration Anaerobic respiration Fermentation Obligate aerobe Obligate anaerobe MicroaerophileReferences edit a b c d Andre Antonin C Debande Lorine Marteyn Benoit S August 2021 The selective advantage of facultative anaerobes relies on their unique ability to cope with changing oxygen levels during infection Cellular Microbiology 23 8 e13338 doi 10 1111 cmi 13338 ISSN 1462 5814 PMID 33813807 S2CID 233027658 Muller Volker 2001 04 19 Bacterial Fermentation eLS doi 10 1038 npg els 0001415 ISBN 9780470016176 Ryan KJ Ray CG eds 2004 Sherris Medical Microbiology 4th ed McGraw Hill pp 261 271 273 296 ISBN 0 8385 8529 9 Singleton P 1999 Bacteria in Biology Biotechnology and Medicine 5th ed Wiley pp 444 454 ISBN 0 471 98880 4 Carlile MJ Watkinson SC Gooday GW 2001 The Fungi 2nd ed Academic Press pp 85 105 ISBN 0 12 738446 4 Schottler U November 30 1979 On the Anaerobic Metabolism of Three Species of Nereis Annelida PDF Marine Ecology Progress Series 1 249 54 Bibcode 1979MEPS 1 249S doi 10 3354 meps001249 ISSN 1616 1599 Retrieved February 14 2010 Yamamoto N amp Droffner M L 1985 Mechanisms determining aerobic or anaerobic growth in the facultative anaerobe Salmonella typhimurium Proceedings of the National Academy of Sciences 82 7 2077 2081 https doi org 10 1073 pnas 82 7 2077 Doelle H W 1974 Dimeric and tetrameric phosphofructokinase and the Pasteur effect in Escherichia coli K 12 FEBS Lett 49 2 220 222 PII 0014 5793 74 80516 8 core ac uk Pasteur L 1857 Memoire sur la fermentation applee lactique Dissertation on the fermentation called lactic Comptes rendus de l Academie des Sciences in French 45 913 916 1032 1036 Rolfe M D Ocone A Stapleton M R Hall S Trotter E W Poole R K amp Green J 2012 Systems analysis of transcription factor activities in environments with stable and dynamic oxygen concentrations Open biology 2 7 120091 https doi org 10 1098 rsob 120091 a b Unden Gottfried Trageser Martin 1991 Oxygen regulated gene expression in Escherichia coli Control of anaerobic respiration by the FNR protein Antonie van Leeuwenhoek 59 2 65 76 doi 10 1007 BF00445650 ISSN 0003 6072 PMID 1854188 S2CID 33083164 Ginger Michael L Fritz Laylin Lillian K Fulton Chandler Cande W Zacheus Dawson Scott C 2010 12 01 Intermediary Metabolism in Protists a Sequence based View of Facultative Anaerobic Metabolism in Evolutionarily Diverse Eukaryotes Protist 161 5 642 671 doi 10 1016 j protis 2010 09 001 ISSN 1434 4610 PMC 3021972 PMID 21036663 Jennewein Jonas Matuszak Jasmin Walter Steffi Felmy Boas Gendera Kathrin Schatz Valentin Nowottny Monika Liebsch Gregor Hensel Michael Hardt Wolf Dietrich Gerlach Roman G Jantsch Jonathan December 2015 Low oxygen tensions found in S almonella infected gut tissue boost S almonella replication in macrophages by impairing antimicrobial activity and augmenting S almonella virulence Hypoxia and Salmonella replication Cellular Microbiology 17 12 1833 1847 doi 10 1111 cmi 12476 PMID 26104016 External links editFacultative Anaerobic Bacteria Obligate Anaerobic Bacteria Anaerobic Bacteria and Anaerobic Bacteria in the decomposition stabilization of organic matter Archived 2009 02 05 at the Wayback Machine Retrieved from https en wikipedia org w index php title Facultative anaerobic organism amp oldid 1216227796, wikipedia, wiki, book, books, library,
